3rd Democratic debate: Candidates clashed on health care, immigration and more

The 10 highest-polling candidates appeared for a single night of debate in Houston hosted by ABC News and Univision -- the smallest roster yet in the third matchup of Democratic National Committee-sanctioned primary debates, with a field that still counts 20.

Here's how the night is unfolding. Please refresh for live updates.

11:52 p.m. Native Texas O'Rourke doubles down on his mandatory buyback stance post-ABC debate

Following one of the key moments of the ABC News/Univision debate, when former Texas Rep. Beto O'Rourke passionately said, "Hell yes, we're going to take away your AR-15, your AK-47," in the spin room, he expanded on his stance, with no spin.

"I used to brag about how safe El Paso was," he said. "One of the safest cities in America and I did so, in part, to make the point we're safe not despite, but because we're a city of immigrants, and the sons and daughters of immigrants. Yet that very fact is what drew that killer to us with a weapon of war he should have never been able to buy."

"We're a nation of laws and I fully believe in this country in my fellow Americans," he continued. "Gun owners and non-gun owners alike, Republicans, independents, and Democrats. I went to a gun show the day after I announced that proposal and listened to people who own AR-15s. Many of them said, I would willingly give that weapon up, I don't need it."

He then added: "I think that's the way forward is make sure that we ask every American to do the right thing. But then we take action. After years, decades of doing nothing in the face of this violence."

11:46 p.m. Warren tells ABC's post-debate panel how she separated herself

Massachusetts Sen. Elizabeth Warren recapped her debate performance, fielding a question on how she separated herself from the other frontrunners.

"I got out there and talked about what I believe in," she said. "I got out there and talked about the things I'm fighting for. I got a chance to talk with America about the importance of public schools. How I've wanted to be a school teacher sinceI was in second grade. I just think it's a terrific opportunity, these debates, for each one of us on that stage to be able to talk with the American people about who we are, and if you give us the chance, where we want to lead this country. All I hope for is that I was as clear as I could be."

11:37 p.m.: Klobuchar pitches herself as a candidate who can unite a unique Democratic coalition, says it's too early to say she hasn't 'caught on'

Sen. Amy Klobuchar said that it is too early in the Democratic primary process to say who the eventual nominee of the party will be."First of all, I'm ahead of 18 people including every governor and the mayor of New York City, so let's keep it in perspective. And secondly, fall is when things start. In Minnesota, in Iowa, in New Hampshire, people are in little league games," Klobuchar told ABC News Chief National Affairs Correspondent Tom Llamas in the spin room after the debate.

11:31 p.m.: Harris defends her prosecutorial record, says she's still introducing herself to the American people

Sen. Kamala Harris defended her prosecutorial record in the spin room after ABC News' Democratic debate, and challenged the notion that she does not have support in the African-American community.

"I did the work that I did was the work of, first of all, becoming a prosecutor, because I just have a very strong and natural desire to want to protect people. In particular our most vulnerable. A large part of my career as a courtroom prosecutor was handling cases that affected crimes against women and children," Harris said.

"There's an incredible amount of support there. Listen, I am still introducing myself to the American people. I have not run before for president. We have a couple of people on the stage who have run once and some many times. I am still introducing myself to people and working on earning the votes of people," Harris said about her strategy to court African-American voters.

11:17 p.m.: Castro defends his attack on Biden during the debate

Former Housing and Urban Development Julián Castro defended a contentious exchange with former Vice President Biden on the debate stage over healthcare, telling ABC News Chief National Affairs Correspondent Tom Llamas: "No, we were having a debate about health care policy."

When asked if the exchange was meant as a slight at Biden's age, Castro said definitively, no.

"I wasn't taking a shot at his age, I was taking a shot at the fact that he had just said the words "Buy in." You would have to buy in," Castro said.

"It's not an attack on Vice President Biden. It's not something about personality. It's about the health care policy. That was my focus," he added.

11:11 p.m.: Buttigieg takes aim at liberals Warren, Sanders from the spin room

South Bend Mayor Pete Buttigieg went after his Democratic rivals, Elizabeth Warren and Bernie Sanders, as he pitched his vision for the country.

"No question that my vision is different," he said. "It's not just about what's attainable, it's about what the right policy is. I view it differently from Senators Sanders and Warren who think we can throw the switch on this big part of the American economy. With health care, I think it's better to trust Americans to make that decision for themselves."

He also tackled the question of electability, when asked by ABC News' Senior Washington reporter, Devin Dwyer, "Electability is one of the main reasons I think people should support me. Every time Democrats have won, not just in my lifetime -- we're going to get out there and campaign are. The best way to demonstrate you're electable is to win. That's what we're seeking to do in the early states. Think about this. Every single time, the democratic party has won not just in my lifetime, the last 50 years, it's been with somebody who came from outside Washington. Somebody who represented a new generation in a different set of ideas. By contrast, every time we've tried the safe choice."

11:07 p.m.: Booker says debate went 'really, really well'

Sen. Cory Booker told ABC News Chief National Affairs Correspondent Tom Llamas in the spin room that Thursday's debate put on display the differences in the Democratic field, but also demonstrated his ability to unify the party.

"I think this was yet another opportunity for me to not only show my ideas, but also the spirit of our party. That stage and all the differences that people were trying to make amongst democrats, to me that's important and our differences matter," Booker said."But what matters a lot more is who can unify our party and the disparate voices so we can beat Donald Trump. Even more importantly than that, who can help unify this country that has suffered, really, under a president that's demeaning and degrading and dividing people. So I think I got a chance to show my ability to pull people together," he added.

11:03 p.m.: Stepping off the debate stage, Sanders touts his performance in the spin room

Vermont Sen. Bernie Sanders reiterated the differences that divide him from the primary's polling frontrunner, Joe Biden.

"I hope so," he said when asked if he made a clear difference between him and former Vice President Biden. "Joe and I have a very different vision for this country. Joe is a good friend of mine. I like him very much. He's a very decent human being. But Joe and I have a very different voting record and a very different vision for this country."

In the post-debate interview, when pressed on if there is room in the field for both him and Warren, Sanders said, "You can ask Senator Warren that. I'm sure she has a good answer. All I can focus on is my campaign. I have been there. Four years ago, I made a decision that I did not want democratic primary to simply be a primary in which the needs of working people were not represented. And I got into that primary. I took on the whole bloody establishment."

10:45 p.m. The debate has ended

The candidates are all smiles and Andrew Yang even blew a kiss as they left the stage.

10:42 p.m.: Klobuchar, Castro highlight family history in closing question

Minnesota Sen. Amy Klobuchar highlighted her struggles with her father's alcoholism as the catalyst for leading her into public service.

"My challenges and resilience have brought me up here," she said. "I grew up with a dad who struggled with alcoholism his whole life and after his third DWI, he had a choice between jail and treatment. He chose treatment...And that made me interested in public service, because I feel like everyone should have that same right, to be pursued by grace."

Former Housing and Urban Development Secretary Julián Castro talked about growing up in a single-parent household to talk about his resiliency, "I shouldn't be here on this stage. You know, Castro is my mother's name and was my grandmother's name before her. I grew up in a single-parent household on the west side of San Antonio, going to the public schools."

He added: "There's nobody that gets tested more in a position of public trust than the president of the United States. This president has failed that test. But I want you to know that if you elect me president, I won't."

10:40 p.m.: Booker reflects on his political legacy, O'Rourke invokes El Paso's resiliency

Reflecting on resiliency, Sen. Cory Booker and former Texas Congressman Beto O'Rourke shared the stories of the communities that they call home.

"My biggest professional setback is embarrassing, because a lot of folks know about it. I, with a bunch of tenant leaders in Newark, New Jersey, in 2002 took on the political machine, and boy did they fight back," Booker said.

"The lesson I learned of resilience is to trust people because the power of the people is always greater than the people in power. And the test of America right now is not a referendum on Donald Trump, it's a referendum on us and who we are and who we're going to be together," Booker said.

O'Rourke told the story of a soccer coach who was shot in El Paso last month, and his desire to continue to do his job, and spoke to the city's ability to come together in the face of tragedy.

"Everything that I've learned about resilience I've learned from my hometown of El Paso, Texas. In the face of this act of terror that was directed at our community, in large part by the president of the United States, that killed 22 people and injured many more, we were not defeated by that, nor were we defined by that," O'Rourke said.

10:36 p.m.: Yang highlights his struggles with entrepreneurship

"I was an unhappy lawyer for five whole months and I left to start a business," Andrew Yang began. "My company flopped. I lost investors, hundreds of thousands of dollars, still owed 100,000 in school debt. My parents still told people I was a lawyer."But he said he persisted: "I kept working in small growth companies for another ten years and eventually had some success. After I had some success, I still remembered how hard it was."

Yang pointed to one of his guests in the audience, Shawn Wynn, a young entrepreneurs who was supported by Yang's nonprofit, Venture for America. He told him he hoped his path was a little bit easier than his own.

10:34 p.m.: Buttigieg gets candid about coming out and the struggles afterwards

South Bend, Indiana Mayor Pete Buttigieg, who is openly gay, got candid about his decision to come out and the response he got afterwards.

"As a military officer serving under don't ask, don't tell, and as an elected official in the state of Indiana when Mike Pence was governor, at a certain point, when it came to professional setbacks, I'd wonder whether just acknowledging who I was, was going to be the ultimate career-ending professional setback," Buttigieg said.

"I had no idea what kind of professional setback it would be, especially because inconveniently, it was an election year in my socially conservative community. What happened was that when I trusted voters to judge me based on the job that I did for them, they decided to trust me and re-elected me with 80% of the vote," he added.

10:29 p.m.: Warren, Sanders and Harris show resiliency through their personal backgrounds

Massachusetts Sen. Elizabeth Warren, taking the final question on personal resiliency, said, "I've known what I wanted to be since second grade. I wanted to be a public school teacher...By the time I graduated from high school, my family didn't have money for a college application, much less to send me off to four years at a university...I made it as a special needs teacher."

She continued: "Here's resilience. I said, I'll go to law school. I practiced law for about 45 minutes and then went back to my first love, which is teaching...the reason I'm standing here today is because I got back up, I fought back. "

Vermont Sen. Bernie Sanders talked about his upbringing in a rent-controlled apartment in Brooklyn, New York, and his unlikely political rise to the U.S. Senate.

"Resilience, to me, means growing up in a rent-controlled apartment in Brooklyn, New York, the son of an immigrant who came to this country without a nickel in his pocket. Professional resilience means to me, George, running for U.S. Senate in Vermont and getting 1% of the vote," Sanders said in response to ABC News Chief Anchor George Stephanopoulos' question.

California Sen. Kamala Harris answered by ticking through her many uphill battles on her way to becoming a U.S. Senator: "I was the only black elected -- woman black elected attorney general in the state, in the country. And each time, people would say, it's not your time, it's not your turn, it's going to be too difficult, they're not ready for you, and I didn't listen."

10:25 p.m.: Biden interrupted by protests in the debate hall

Former Vice President Biden was interrupted by protesters during an answer on what the most significant professional setback he's faced was.

It was not immediately clear what the protesters were shouting.

"My dad had an expression. He said, Joey, it's not a question of succeeding, whether you get knocked down, it's how quickly you get up, and he said, you never explain and never complain," Biden said after the protesters were removed rom the debate hall.

10:17 p.m. Who has had the most speaking time in the Democratic debate?

Former Vice President Joe Biden led the first half of Thursday night's Democratic debate in speaking time. Biden spoke for 9:52. He spoke the most words in both previous debates, according to FiveThirtyEight.

10:19 p.m.: Booker returns to his roots in Newark to debate charter schools

Seeking to find a lane amid a debate on charter schools, New Jersey Sen. Cory Booker invoked his mayoral tenure, saying, "People are talking about raising teacher salary. We actually did it in Newark, New Jersey."

"We didn't stop there," he said. "We closed poor-performing charter schools, but we expanded high-performer charter schools. We were a city that said, we need to find local solutions that work for our community."

10:15 p.m.: Biden pressed on his record on race relations

Former Vice President Joe Biden was pressed by ABC News' National Correspondent Linsey Davis on his record on race relations, which he defended vigorously.

"Look, there's institutional segregation in this country. And from the time I got involved, I started dealing with that. Red lining, banks, making sure we are in a position where -- look, you talk about education. I propose that what we take is those very poor schools, the Title I schools, triple the amount of money we spend from $15 to $45 billion a year," Biden said.

Biden also used his time to answer a previously asked question about Venezuela.

"I'm going to go like the rest of them do, twice over. Okay? Because here's the deal. The deal is that we've got this a little backwards. By the way, in Venezuela, we should be allowing people to come here from Venezuela. I know Maduro. I've confronted Maduro. Number two, you talk about the need to do something in Latin America," Biden said.

10:10 p.m.: Warren touts her past career as a public school teacher

Massachusetts Sen. Elizabeth Warren chimed in on the debate over public education, touting her background as a public school teacher.

"I think I'm the only person on this stage who has been a public school teacher," Warren said. "I've wanted to be a public school teacher since I was in second grade. And let's be clear in all the ways we talk about this, money for public schools should stay in public schools. Not go anywhere else. I've already made my commitment."

"We will have a secretary of education who has been a public school teacher," she insisted.

10:08 p.m.: Buttigieg goes after Education Secretary Betsy DeVos as he advocates for paying teachers more

Mayor Pete Buttigieg, garnering loud cheers from the crowd, went after President Trump's Secretary of Education Betsy DeVos.

"Step one is appoint a Secretary of Education who actually believes in public education. I believe in public education. And in order to strengthen it, some things are very complex, for preparing for a future where knowledge is at your fingertips, but we got to teach more to do with critical thinking and social and emotional learning," Buttigieg said.

"If we want to get the results that we expect for our churn, we have to support and compensate the teaching profession. Respect teachers the way we do soldiers and pay them more the way we do doctors," he argued.

10:06 p.m.: Yang defends his support for charter schools

Andrew Yang, one of the most vocal proponents for charter schools, said on his support, "I am pro-good school. I've got a kid, one of my little boys just started public school last week, and I was not there because I was running for president.

He then paused for a second, before adding, "We need to pay teachers more, because the data clearly shows that a good teacher is worth his or her weight in gold."

"The answer is to put money directly into the families and neighborhoods to give our kids chance to learn and our teachers a chance to teach," he concluded.

10:12 p.m.: Harris touts her plan for Historically Black Colleges and Universities (HBCUs)

Sen. Harris, a graduate of Howard University, touted her plan to invest more in Historically Black Colleges and Universities (HBCUs) like Texas Southern University.

"I also want to talk about where we are here at TSU, and what it means in terms of HBCUs. I have -- as part of my proposal, that we will put $2 trillion into investing in our HBCUs for teachers, because -- because -- because, one, as a proud graduate of a historically black college and university, I will say -- I will say that it is our HBCUs that disproportionately produce teachers and those who serve in these positions," Harris said.

10:05 p.m.: Warren again casts corporate America as the culprit for lack of action on climate change, Harris calls out Republicans on the issue

The discussion on climate change continued with Senators Warren on Harris, who each cast the issue as one of the utmost importance.

"We need to work on every front on climate change. It is the threat to every living thing on this planet and we are running out of time," Warren said.

Harris went after congressional Republicans over the issue, saying that their inaction shows a "lack of courage."

"When I've been in the United States Senate for now the last two and a half years and I look at our counterparts, the Republicans in the United States Senate, they must be looking at their children and then when they look at the mirror, I don't know what they see, but it's a lack of courage," Harris said.

10:02 p.m.: Klobuchar pitches a Midwesterner's approach to climate change

Minnesota Sen. Amy Klobuchar leaned into her Midwestern roots to outline her approach to tackling the climate crisis, "I think having someone leading the ticket from the midwest will allow us to talk about this in a different way and get it done."She continued: "On day one, I will get us back into the international climate change agreement. On day two, I will bring back the clean power rules that president Obama had worked on."

10:00 p.m.: O'Rourke says he will take action on climate change 'regardless of political consequences'

Former Texas Congressman Beto O'Rourke, responding to a question on climate change, said action on the issue is crucial "regardless of political consequences."

"We will follow through, regardless of the political consequences or who it offends, because this is the very future of our planet and our ability for our children and grandchildren to be able to survive on it," O'Rourke said.

"We will make sure that we get to net zero greenhouse gas emissions no later than the year 2050, that we are halfway there by 2030, that we mobilize $5 trillion over the next ten years to do that, that we invest here in Houston, Texas, with pre-disaster mitigation grants to protect those communities that are vulnerable to flooding, given the fact that this town has seen three 500-year floods in just five years," O'Rourke added.

9:52 p.m.: Sanders contrasts his Iraq war vote with Biden's

Vermont Sen. Bernie Sanders called out former Vice President Joe Biden's 'yes' vote on the Iraq war in 2003 - when he was a senator from Delaware.

"The big differences between you and me, I never believed what Cheney and Bush said about Iraq and I voted against the war in Iraq and help lead the opposition," Sanders said. "I think also I am the only person up here to have voted against all three of trump's military budgets."

9:49 p.m.: Biden defends his record on Iraq, Afghanistan

Former Vice President Biden, who has taken criticism recently for his record on foreign policy, and his vote in favor of the Iraq War, defended his record, and said he was wrong to say he opposed the war immediately after it started.

"With regard to Iraq, the fact of the matter is that, you know, I should have never voted to give bush the authority to go in and do what he did," Biden said.

"I said something that was not meant the way I said it. I said, from that point on. What I was arguing against in the beginning, once he started to put the troops in, was that in fact we were doing it the wrong way, there was no plan," Biden said.

He later leaned on the trust President Obama put in him to ensure an effective end to U.S. involvement in Iraq.

"And it was later when we came into office, that Barack - the president - turned to me, he said, Joe, we have a plan to get out. He turned, he said, Joe will organize this, get the troops home.."

9:46 p.m.: Buttigieg, only military veteran on stage, advocates against 'endless wars'

South Bend, Indiana Mayor Pete Buttigieg, a U.S. Navy veteran and the only candidate on stage Thursday with military experience, advocated for a drawdown of the War in Afghanistan.

"If there's one thing we've learned about Afghanistan, from Afghanistan, it's that the best way not to be caught up in endless war is to avoid starting one in the first place. And so when I am president, an authorization for the use of military force will have a built in three-year sunset," Buttigieg said.

"By the way, we also have a president right now who seems to treat troops as props, or worse, tools for his own enrichment," he added, taking a swipe at Trump.

9:44 p.m.: Warren takes up the issue of bringing troops home

When asked by "World News Tonight" Anchor and Managing Editor David Muir about keeping her promise to bring troops home starting now, without a deal with the Taliban, Massachusetts Sen. Elizabeth Warren responded, "What we're doing right now in Afghanistan is not helping the safety and security of the United States, it is not helping the safety and security of the world, it is not helping the safety and security of Afghanistan."

"We need to bring our troops home," she said. "Then we need to make a big shift. We can not ask our military to keep solving problems that cannot be solved militarily."

During a follow up, Warren invoked her trip to Afghanistan with the late Sen. John McCain, to elevate her foreign policy credentials.

"I was in Afghanistan with John McCain two years ago this past summer," she said. "We talked to military leaders, American and local leaders, we talked to people on the ground and asked the question...Show me what winning looks like...no one can describe it. And the reason no one can describe it is because the problems in Afghanistan are not problems that can be solved by a military."

9:42 p.m.: Booker gives a shoutout to Canadian Prime Minister Justin Trudeau, and his hair

Hitting President Trump over his aggressive trade policies, including slapping tariffs on Canadian goods, Booker gave a shoutout to Prime Minister Justin Trudeau.

"You literally have him using a national security waiver to put tariffs on Canada. I'm the only person on this stage that finds Trudeau's hair very menacing, but they are not a national security threat," the famously bald Booker said.

"We cannot go up against China alone. This is a president that has a better relationship with dictators like Duterte and Putin than he does with Merkel and Macron," Booker said, invoking President Trump's foreign policy strategy, which Democrats charge is too cozy with authoritarian regimes.

9:40 p.m.: Moderate Biden finds common ground with liberal warren

In a rare moment of comity, former Vice President Joe Biden said he agreed with Massachusetts Sen. Elizabeth Warren.Amid the debate on trade, he said, "I think Elizabeth -- Senator Warren is correct, at the table has to be labor, and at the table have to be environmentalists. The fact of the matter is, China, the problem isn't the trade deficit, the problem is they're stealing our intellectual property."

9:36 p.m.: Harris navigates the debate on trade

California Sen. Kamala Harris, who was asked how her trade policy would differ than former President Obama's, said, "When we look at this issue, my trade policy, under a Harris administration, is always going to be about saying, we need to export American products, not American jobs. And to do that, we have to have a meaningful trade policy. I'm not a protectionist Democrat. Look, we need to sell our stuff. And that means we need to sell it to people overseas."

As she has done several times throughout the debate, Harris then hit at President Trump, asserting in jest, "But the bottom line is this, Donald Trump in office on trade policy, you know, he reminds me of that guy in "The Wizard of Oz," you know, when you pull back the curtain, it's a really small dude?"

9:31 p.m.: Klobuchar says Trump is treating farmers and workers like 'poker chips'

As she directed her criticism at President Trump, the frequent target of attacks Thursday night, Minnesota Amy Klobuchar said, "What [Trump] has done here, has assessed these tariffs on our allies, he's put us in the middle of the trade war and treating our farmers and workers like poker chips in one of his bankrupt casinos."

9:31 p.m.: Klobuchar says Trump is treating farmers and workers like 'poker chips'

As she directed her criticism at President Trump, the frequent target of attacks Thursday night, Minnesota Amy Klobuchar said, "What [Trump] has done here, has assessed these tariffs on our allies, he's put us in the middle of the trade war and treating our farmers and workers like poker chips in one of his bankrupt casinos."

9:29 p.m.: Yang, Buttigieg criticize Trump's trade strategy with China

Both Yang and Buttigieg criticized President Trump's strategy in dealing with China, and the South Bend Mayor calling him an "empty chair" on the global stage.

"We have to let the Chinese know that we recognize that President Trump has pursued an arbitrary and haphazard trade policy that has had victims on both sides," Yang said.

"Well, the president clearly has no strategy. You know, when I first got into this race, I remember president Trump scoffed and said he'd like to see me make a deal with Xi Jinping. I'd like to see him making a deal with XI Jinping. Is it just me or was that supposed to happen in like April?" Buttigieg asked rhetorically.

Pete Buttigieg on trade: "When I first got into this race, I remember President Trump scoffed and said he'd like to see me making a deal with Xi Jinping. I'd like to see him making a deal with Xi Jinping" https://t.co/T37EaVOvlU #DemDebate pic.twitter.com/P3kK7Om1hr

- ABC News Politics (@ABCPolitics) September 13, 2019

9:19 p.m.: Buttigieg: 'Anyone who supports this president is supporting racism'

Fielding a question from Univision's Jorge Ramos, South Bend, Indiana Mayor Pete Buttigieg gave a stark answer on President Trump's supporters when it comes to the issue of immigration.

"Anyone who supports this is supporting racism...The only people, though, who actually buy into this president's hateful rhetoric around immigrants are people who don't know any," Buttigieg said.

He also said as president he will get comprehensive immigration reform done.

"We have an opportunity to actually get something done. But we cannot allow this continue to be the same debate with the same arguments and the same clever lines often among the same people since the last real reform happened in the 1980s," he warned.

9:16 p.m.: Yang fields question on legal immigration

Entrepreneur Andrew Yang invokes his ancestry when talking about legal immigration, "My father grew up on a peanut farm in Asia with no floor and now his son is running for president. That is the immigration story."

Yang continued: "We have to say to the American people, immigrants are positive for our economic and social dynamism, and I would return immigration to the total it was in the Obama administration."

He also took aim at the current president, telling the crowd: "I am the opposite of Donald Trump in many ways. He says, 'build a wall.' I'm going to say to immigrants, 'come to America, because if you come here, your son our daughter can run for president.'"

9:13 p.m.: Castro again expresses frustration over Obama administration's lack of action on immigration reform, lashes Biden over invoking his former boss

After Biden defended the Obama administration's record on immigration, Castro criticized the former Vice President for invoking his former boss only when it's convenient.

"My problem with Vice President Biden, and [Senator Booker] pointed this out last time is, every time something good about Barack Obama comes up, he says, oh, I was there, I was there, I was there, that's me, too, and then every time somebody questions part of the administration that we were both part of, he says, well, that was the president," Castro said.

"I stand with Barack Obama all eight years. Good, bad and indifferent. That's where I stand. I did not say I did not stand with him," Biden said in defense.

9:10 p.m.: Univision Anchor Jorge Ramos questions Biden on immigration

When tasked with defending former President Barack Obama's record on deportations, former Vice President Joe Biden said, "What Latinos should look at, comparing this president to the president we have is outrageous, number one. We didn't lock people up in cages. We didn't separate families."

You didn't answer the question," Ramos said.

"Well, I did answer the question," Biden responded.

"Did you make a mistake with those deportations," Ramos posed.

"The president did the best thing that was able to be done," Biden said.

Ramos replied, "How about you?"

Biden said: "I'm the vice president of the United States."

9:07 p.m. Fact-checking Democratic candidates on the issues at the ABC News debate in Houston

ABC News is fact checking the Democratic Debate in Houston between Sen. Amy Klobuchar, Sen. Cory Booker, Mayor Pete Buttigieg, Sen. Bernie Sanders, former Vice President Joe Biden, Sen. Elizabeth Warren, Sen. Kamala Harris, Andrew Yang, former Rep. Beto O'Rourke and former Housing and Urban Development Secretary Julian Castro.

9:06 p.m.: Warren reaffirms support for eliminating the filibuster for gun control

Massachusetts Sen. Elizabeth Warren pivoted from mass shootings to talk about the gun violence epidemic happening everyday in the country.

"People die from violence from suicide and domestic abuse. We have a gun violence problem in this country," she said before reiterating her support for eliminating the filibuster to take action on gun reform. "I was in the United States Senate when 54 Senators said, 'let's do background checks, let's get rid of assault weapons' and with 54 Senators, it failed because of the filibuster. Until we attack the systemic problems, we can't get gun reform in this country."

9:04 p.m. Booker says action on gun control can't wait until tragedy reaches more communities

Sen. Booker pushed an urgent response to the recent mass shootings, saying that action cannot only come after those tragic events, but also in response to violence in the communities like his (Booker resides in Newark, New Jersey).

"I'm happy that people like Beto O'Rourke are showing such courage now and coming forward and also now supporting licensing. But this is -- what I'm sorry about, I'm sorry that it had to take issues coming to my neighborhood or personally affecting Beto to suddenly make us demand change," Booker said.

"We have had more people die due to gun violence in my lifetime than every single war in this country combined from the revolutionary war until now. This is not a side issue to me. It is a central issue to me," Booker said in response to a follow up question from World News Tonight Anchor David Muir.

8:59 p.m.: O'Rourke maps out his plan for mandatory buybacks

When asked if he would implement mandatory buybacks for assault-style weapons, former Texas Congressman Beto O'Rourke says, "I am, if it's a weapon that was designed to kill people on a battlefield."

O'Rourke grew more passionate, as he continued: "So many other people were shot by that AR-15 in Odessa, there weren't enough ambulances to get to them in time. Hell yes, we're going to take away your AR-15, your AK-47. We're not going to allow it to be used against a fellow American anymore."

8:57 p.m. Harris again calls back to Obama, also praises O'Rourke's response to the El Paso shooting

Harris, as multiple candidates on stage have already done, invoked former President Barack Obama and his signature campaign slogan when discussing her ability to carry out gun control via executive order.

"Yes, we can, because I'll tell you something. The way that I think about this is, I've seen more autopsy photographs than I care to tell you. I have attended more police officer funerals than I care to tell you. I have hugged more mothers of homicide victims than I care to tell you," Harris said.

She also praised Congressman O'Rourke's response to the mass shooting last month in El Paso, Texas.

"Beto, god love you for standing so courageously in the midst of that tragedy. You know, people asked me in El Paso, they said, you know, because I have a long-standing record on this issue," Harris said.

8:54 p.m.: Gun control takes center stage at the third Democratic debate, with El Paso survivors in the audience

Former Vice President Joe Biden says that since Sandy Hook, gun control "went from a cause to a movement."

He then praised former Texas Congressman Beto O'Rourke for his response to the El Paso shooting:

"By the way Beto -- forgive me for saying Beto," Biden said.

O'Rourke responded: "That's okay. Beto's good."

Biden continued: "The way he handled what happened in his hometown is meaningful. To look into the eyes of those people, to see those kids, to understand those parents, you understand the heartache. But this is the problem. This is the problem."

8:49 p.m.: Klobuchar defends her record as a prosecutor in Minnesota

When Minnesota Sen. Amy Klobuchar was pressed on her eight-year tenure as a prosecutor in Minnesota, in which dozens of incidents where black men were killed by police, she responded, "That's not my record ... when I was there, the way we handled these police shootings, I actually took a stand to make sure outside investigators handled them."

She added: "I will make sure we don't just do the First Step Act when it comes to criminal sentencing, that we move to the Second Step Act."

8:47 p.m.: Conversation turns to criminal justice reform, and Harris' prosecutorial record comes under scrutiny

The conversation around racism then turned towards criminal justice reform, and Sen. Kamala Harris' record as a prosecutor came under direct scrutiny, a record she defended.

"I'm glad you asked me this question, and there have been many distortions of my record. Let me be very clear. I made a decision to become a prosecutor for two reasons. One, I've always wanted to protect people and keep them safe and second, I was born knowing about how this criminal justice system in America has worked in a way that has been informed by racial bias," Harris said.

"My plan is about making sure that in America's criminal justice system, we de-incarcerate women and children, that we end solitary confinement and that we work on keeping families intact. And as President of the United States, knowing the system from the inside, I will have the ability to be an effective leader and get this job complete," Harris added.

8:45 p.m.: Buttigieg talks up his 'Douglass Plan'

As he followed suit with his democratic rivals, South Bend Mayor Pete Buttigieg addressed the system racism in the country, saying, it "preceded this president and even when we defeat him, it will be with us."

"That's why we need a systemic approach to dismantle it," he continued. "It's -- it's not enough to just take a racist policy, replace it with a neutral one and expect things will just get better on their own ... This time, a Douglass plan that we invest right here at home. To make sure that we're not only dealing with things like the over-incarceration of black Americans."

8:43 p.m.: Booker pitches a new path forward to attack 'systemic racism'

Booker, fielding a question from ABC News' Linsey Davis, said a comprehensive criminal justice plan is central to combatting "systemic racism,' in America.

"Racism exists, the question isn't who isn't a racist, it's who is and isn't doing something about racism," Booker said.

"It's nice to go back to slavery, but we have a criminal justice system that is so racially biased, we have more African-Americans under criminal supervision today than all the slaves in 1850. We have to come at this issue attacking systemic racism, having the courage to call it out and having a plan to do something about it," he added.

8:41 p.m.: O'Rourke tackles racism in America standing on the stage of HBCU Texas Southern University

When asked about addressing the racial divide in the country, former Texas Congressman Beto O'Rourke said, "Racism in America is endemic. It is foundational...I'm going to follow Sheila Jackson Lee's lead and sign a reparations bill that will allow us to address this at its foundation. But we will also call out the fact that we have a white supremacist in the white house and he poses a mortal threat to people of color all across this country."

The other Texan on stage, former Housing and Urban Development Secretary Julián Castro chimed in, first praising O'Rourke for his response to the El Paso shooting, and then arguing, "We need to root out racism and I believe we can do that, because that doesn't represent the vast majority of Americans who do have a good heart. They need a leader to match that and I will be a president that matches that."

8:38 p.m.: Outsider Yang injects his business background in health care debate

Amid a tense moment between some of his fellow contenders, Andrew Yang said, "We know we're on the same team here. We know we're on the same team. We all have a better vision for health care than our current president."

He then continued: "I believe we're talking about this the wrong way. As someone who has run a business, I know that our current health care system makings it harder to hire people, makes it harder to give them benefits and treat them as full-time employees. It's harder to change jobs. It's certainly harder to start a business. The pitch we have to make to the American people is, we will get the health care weight off of your backs and then unleash the hopes and dreams of the American people."

8:36 p.m.: Castro goes directly after Biden, Buttigieg, Klobuchar tries to be the voices of reason

Former Housing and Urban Development Secretary Julián Castro and Biden had a particularly contentious exchange, also over healthcare, with Castro accusing Biden of forgetting the details of his own healthcare plan.

"Are you forgetting what you said two minutes ago? Are you forgetting already what you said just two minutes ago? I can't believe that you said two minutes ago that they had to buy in, and now you're saying they don't have to buy in. You're forgetting that," Castro said to gasps from the audience.

"I said anyone like your grandmother who has no money," Biden said in defense.

"This is why presidential debates are becoming unwatchable. This reminds everybody of what they cannot stand about Washington. Scoring points against each other. Poking at each other," Buttigieg said.

"A house divided cannot stand. And that is not how we're going to win this," Klobuchar said.

8:35 p.m.: Texas native O'Rourke argues some Democrats are offering a 'false choice'

Former Texas Congressman Beto O'Rourke spoke directly to his fellow Democrats to tell them, "we've got to do better.""I also think we're being offered a false choice between those who propose an all or nothing gambit, forcing tens of millions off of insurance that they like, that works for them, to force them onto medicare and others who want to, as the vice president does, incrementally improve what we have, which will leave many, maybe millions uncared for," he said. "We've got to do better."

8:33 p.m.: Biden invokes Sanders 'socialist' label

"If you notice, nobody's yet said how much it's going to cost the taxpayer. I hear this, large savings, the president -- my friend from Vermont thinks that the employer is going to give back if you negotiate as a union all these years, got a cut in wages because you got insurance. They're going to give back that money to the employee?" Biden asked Sanders.

"As a matter of fact, they will," Sanders responded.

"Well let me tell you something. For a socialist you got -- For a socialist, you have a lot more confidence in corporate America than I do," Biden said.

8:31 p.m.: Kamala Harris cheers Obama, slams Trump

After the second Democratic debate saw former President Barack Obama's legacy criticized, California Sen. Kamala Harris praised him: "I want to give credit to Barack Obama for bringing us this far."

She then took aim at the current White House occupants, President Trump, telling the crowd, "But at least five people have talked, some repeatedly on this subject, and not once have we talked about Donald Trump. So let's talk about the fact that Donald Trump came into office and spent almost the entire first year of his term trying to get rid of the Affordable Care Act."

8:29 p.m.: Buttigieg says he 'trusts the American people' on healthcare, Sanders hits back

Buttigieg also went after Medicare for All, and pitched his own plan that he dubs "Medicare for All who want it."

"The problem, Senator Sanders, with the damn bill that you wrote, and that Senator Warren backs, is that it doesn't trust the American people. I trust you to choose what makes the most sense for you. Not my way or the highway," Buttigieg said.

Sanders doubled down on his plan, Medicare for All, "Medicare for All is comprehensive health care. Covers all basic needs, including home health care. It allows you to go to any doctor you want, which many private insurance company programs do not."

8:27 p.m.: Amy Klobuchar seeks to carve out her path on health care by taking aim at Sanders

"Senator Sanders and I have worked valiantly to bring down the cost of pharmaceuticals," said Minnesota Sen. Amy Klobuchar. "And while Bernie wrote the bill, I read the bill. And on page eight -- on page eight of the bill, it says that we will no longer have private insurance as we know it."

"That means that 149 million Americans will no longer be able to have their current insurance. That's in four years. I don't think that's a bold," she added."

Sen. Amy Klobuchar: "I may not be the loudest person up here, but I think we've already got that in the White House. Houston, we have a problem. We have a guy there that is literally running our country like a game show" https://t.co/T37EaVOvlU #DemDebate pic.twitter.com/oLXwsx3tv6

- ABC News Politics (@ABCPolitics) September 13, 2019

8:25 p.m.: Warren, Sanders join forces to defend health care plans

Both Warren and Sanders again defended their health care plans after Biden pointed out the high cost of the programs they are advocating for.

"So, let's be clear, I've actually never met anybody who likes their health insurance company. I've met people who like their doctors, I met people who like their nurses, I've met people who like their pharmacists, I met people who like their physical therapists. What they want is access to health care," Warren said.

"Let us be clear, Joe, in the United States of America, we have spending twice as much per capita on health care as the Canadians or any other major country on Earth," Sanders argued.

8:23 p.m.: Biden keeps up the fight for Obamacare by taking aim at the progressive tag team

"This is about candor, honesty," the former vice president said. "The tax of 2% that the Senator [Warren] is talking about, that raises about $3 billion. Guess what? That leaves you $28 billion short. The senator said before, it's going to cost you in your -- there will be a deductible - in your paycheck. You're gonna -- The middle class person, someone making 60 grand with three kids, they're going to end up paying $5,000 more."

8:21 p.m.: Sanders forcefully defends Medicare for All after Biden's criticism

Sanders immediately defended his Medicare for All plan, and went after Biden for pushing for "the status quo.""Joe said that Medicare for All would cost over $30 trillion. That's right, Joe, status quo over ten years will be $50 trillion!" Sanders said.

"We need -- we need a health care system that guarantees health care to all people as every other major country does, not a system which provides $100 billion a year in profit for the drug companies and the insurance companies. I'll tell you how absurd the system is tonight on ABC, the health care industry will be advertising, telling you how bad medicare for all is, because they want to protect their profits. That is absurd," Sanders said.

8:20 p.m.: Warren fields question on middle class taxes going up for health care

Massachusetts Sen. Elizabeth Warren hedged when directly asked on if middle class taxes will go up under "Medicare for All""How do we pay for it? We pay for it, those at the very top, the richest individuals and the biggest corporations, are going to pay more. And middle class families are going to pay less," she said. "That's how this is going to work."When pressed again, she responded, "The answer is Medicare for All, costs are going to go up for wealthier individuals and costs are going to go up for giant corporations. But for hard-working families across this country, costs are going to go down and that's how it should work under medicare for all in our health care system."

8:19 p.m.: Biden pushed back on Warren and Sanders' health care plans

Former Vice President Joe Biden kicked off the debate and pushed back on the health care plan being pitched by Warren and Sanders, Medicare for All.

"I think we should have a debate on health care. I think -- I know that [Senator Warren] says she's for Bernie, well, I'm for Barack. I think it worked," Biden said.

"So as far, my distinguished friend, the senator on my left has not indicated how she pays for it and the senator has," Biden said gesturing to Sanders and Warren. "In fact, come forward and said how he's going to pay for it, but it gets him halfway there."

8:17 p.m.: The top four candidates also give opening statements

California Sen. Kamala Harris targets President Donald Trump: "But here's what you don't get. What you don't get you is that the American people are so much better than this. And we know that the vast majority of us have so much more in common than what separates us, regardless of our race, where we live or the party with which we're registered to vote ... And now, President Trump, you can go back to watching Fox News."

Sen. Bernie Sanders, I-Vt., pitched his long-standing message of fundamental economic change to benefit the country's working class: "It goes without saying that we must and will defeat Trump, the most dangerous president in the history of this country. But we must do more. We must do more. We have got to recognize that this country is moving into a form of society where a handful of billionaires control the economic and political life of this country."

Sen. Elizabeth Warren, D-Mass., talks up her Houston roots before touting why she should be at the top of the ticket: "I got my big opportunity about a half mile down the road from here at the University of Houston, back when it cost $50 a semester ... I know what's broken, I know how to fix it and I'm going to lead."

Former Vice President Biden called back to a speech President John F. Kennedy gave when he launched the "Moonshot Program" to land on the moon: "We're walking around with our heads down like "woe is me." We're the best-equipped nation in the world to take this on. It's no longer time to postpone. We should get moving. There's enormous, enormous opportunities once we get rid of Donald Trump," Biden said.

8:12 p.m.: The next series of candidates give opening statements

Former Texas Rep. Beto O'Rourke invokes the shooting of El Paso in his opening remarks: "On August 3rd, in El Paso, Texas, two things became crystal clear for me ... The first is just how dangerous Donald Trump is the cost and the consequence of his presidency ... The second is how insufficient our politics is to meet the threat that we have right now."

New Jersey Sen. Cory Booker struck a unifying tone in his opening statement: "That's the story of America. At our best, we unify, we find common cause and common purpose. The differences amongst us Democrats on the stage are not as great as the urgency for us to unite as a party, not just to beat Donald Trump, but to unite America in common cause and common purpose," Booker said.

South Bend, Ind., Mayor Pete Buttigieg harkened back to the 18th anniversary of the 9/11 terror attacks, saying he wants to focus on the future of the country: "We just marked the anniversary of 9/11. All day today I've been thinking about September 12th, the way it felt when for a moment, we came together as a country. Imagine if we had been able to sustain that unity," Buttigieg said.

8:10 p.m. Andrew Yang officially announced plans to give 10 new individuals $1,000 a month

Entrepreneur Andrew Yang announced on tonight's debate stage 10 new people to receive the "Freedom Dividend," a $1000 a month payment, his signature campaign policy, according to a Yang campaign source. Three people already received the payment from Yang, bring the total number of people receiving the dividend to 13. The source tells ABC News he will use campaign funds to make the payment.

8:05 p.m. Klobuchar ribs Trump in her opening statement

Minnesota Sen. Amy Klobuchar ribbed President Donald Trump in her opening statement at Thursday's debate."I may not be the loudest person up here, but I think we've already got that in the white house. Houston, we have a problem. This -- we have a guy there that is literally running our country like a game show. He would rather lie than lead," Klobuchar said.

8:03: Julián Castro kicks off opening statements

At the onset of the ABC News/Univision debate in Houston, former Housing and Urban Development Secretary Julián Castro delivers his opening statement, the first of the 10 candidates on stage:

"There will be life after Donald Trump. But the truth is that our problems didn't start just with Donald Trump and we won't solve them by embracing old ideas. We need a bold vision," he said. "We have to win... it's what I can do in this race get back Michigan, Wisconsin and Pennsylvania, Florida, Georgia and Arizona and finally turn Texas blue and say good-bye to Donald Trump."

8:00 p.m.: The third Democratic debate gets underway

The third Democratic debate, hosted by ABC News and Univision, is starting from Houston's Texas Southern University.Here's how to watch the debate: The three-hour event airs on ABC, on Univision with a Spanish translation, locally on KTRK-TV and on ABC News Live. The streaming channel is available on the ABCNews.com, Good Morning America and FiveThirtyEight websites and mobile phone apps, as well as on Hulu Live, The Roku Channel, Facebook Watch, AppleTV, Amazon Fire TV, YouTube, Apple News, and Twitter.

7:52 p.m. Andrew Yang plans to give 10 new individuals $1,000 a month

Entrepreneur Andrew Yang will announce on tonight's debate stage 10 new people to receive the "Freedom Dividend," a $1000 a month payment, his signature campaign policy, according to a Yang campaign source. Three people already received the payment from Yang, bring the total number of people receiving the dividend to 13. The source tells ABC News he will use campaign funds to make the payment.

7:49pm The ABC News moderators take the stage

The four moderators for the third Democratic debate - ABC News Chief Anchor George Stephanopoulos, ABC News "World News Tonight" Anchor and Managing Editor David Muir, ABC News Correspondent Linsey Davis and Univision Anchor Jorge Ramos will moderate - introduce the candidates on stage in order of their podium placements:

7:37 p.m. DNC Chair Tom Perez goes in on President Trump "Stop tweeting"

DNC Chair Tom Perez criticized the president, Senate Majority Leader Mitch McConnell and others in Republican leadership, admonishing the president to "stop tweeting" and start governing.

"It's great to be in this battleground and let me reiterate: This is a battleground, my friends!"

7:25 p.m. Wanna know more about how Houston is a look into America's future?

As ten presidential candidates arrive in Houston for the third round of Democratic debates, Houstonians say they will find America's future: young, multicultural and, two years after Hurricane Harvey laid waste to parts of this city, reckoning with the very real threat of climate change. With 2.3 million residents, sprawling Houston is the fourth biggest city in the country, while according to the most recent census, close to two-thirds of the population is non-white and a quarter of residents are foreign-born.

"We know that we cannot let our diversity divide us. We recognize diversity is our strength," Houston Mayor Sylvester Turner told the crowd.

Learn more about the diverse and vibrant city here.

7:20 p.m. Learn more about why it matters that the third presidential debate is being held at historically black university

Bringing an event of this caliber to the school will not only raise national attention to the issues that matter to African American voters, but it will highlight the mission of historically black colleges and universities, also known as "HBCUs", around the country, school officials, graduates and students said.

"We are beyond thrilled to serve as the host for this historic event - one that adds to the incredible legacy of this 92 year-old institution," Texas Southern University President Austin Lane told the gathering.

Notable alumni of Texas Southern include Rep. Al Green, who graduated from the university's Thurgood Marshall School of Law, NFL Hall of Famer and Good Morning America co-host Michael Strahan as well as former congresswoman and civil rights leader Barbara Jordan, who the School of Public Affairs is named after.

Read more here.

7:18 p.m. ABC News president James Goldston addresses the crowd, GMA cohost Michael Strahan sends video message

The crowd warmly receives ABC News president James Goldston as he addresses the gathering and erupts in cheers as GMA cohost Michael Strahan sends his former school warm wished via video message.

7:13 p.m. The debate hall fills

The crowd is gathering, debate hall is filling and excitement is growing ahead of the debate.

7 p.m. ABC News is live from the spin room in Houston

ABC News is live from the spin room in Houston, Texas, with complete coverage and analysis of the Democratic presidential debate.

Catch every minute on ABC News Live or on your favorite streaming device.

6:33 p.m. Check out this time-lapse of ABC News debate prep

Check out this cool time- lapse video showing crews setting up for the third 2020 Democratic primary debate in Houston, Texas.

6: 20 pm Harris shouts out ABC News and HBCU debate host

Earlier on Thursday, Sen. Kamala Harris shouted out debate host site, Texas State University, a public historically black college and the location of ABC News' presidential debate.

"Later today I'll step on stage at @TexasSouthern. As a proud graduate of an HBCU, I'm hopeful this debate will shine a light on what we can do as a nation to strengthen and improve some of our nation's most important higher education institutions."

5:57 p.m. Trump talks debate watch plans, offers thoughts on Democratic candidates

He won't be tuning in live, but President Trump still plans to watch tonight's debate.

"It's too bad I'm going to miss it," Trump said when asked by ABC's Kyra Phillips what he expects from the debate. "I'll have to have it taped. I didn't even tell them about that."

Phillips asked Trump who he thinks his strongest opponent is, and he said he has his eyes on the top three in polls -- Joe Biden, Elizabeth Warren, and Bernie Sanders.

"They all have their weaknesses and their strengths. I think that they are very different. You certainly have a lot of different voices up there. But it would look to me like it would be Elizabeth Warren and looks like Joe maybe will be able to get there, maybe not. I don't know. And certainly Bernie is there. He's number three. But I think that's -- because they are so far in the lead, the three of them," Trump said.

Trump was also asked if he respects any of the Democrats on the debate stage. He said he respects "all of them," despite having made fun of the top contenders numerous times.

"I respect everyone," he said. 'Let me tell you, it takes a lot of courage to run for office. I respect all of them. See that. I'm getting to be much better as a politician. You never thought you'd hear that answer."

ABC News' Meridith McGraw and Kyra Phillips contributed to this report.

5:32 p.m. - Biden advisers lay out debate objectives

Senior advisers to former Vice President Joe Biden told ABC News that they have three objectives they hope to accomplish in tonight's debate: (1) Argue that action -- not just plans -- is needed, and that Biden has a proven record of getting things done; (2) defend the Obama administration's record, and argue that building on that legacy is the best course of action; (3) push back on the notion that Biden's ideas are merely incremental.

The advisors said that Biden is not on the stage to attack other Democrats, but said that he would be pointing out substantive policy differences between himself and other candidates on the stage-listing Warren and Sanders by name.

"You will see him raise questions about how some of these plans that not just Senator Warren but Senator Sanders and others bring forward. how they're going to be paid for and how they'll be implemented," a senior adviser said.

The advisers were twice asked about how Biden would deal with Senate Majority Leader Mitch McConnell specifically on guns, to which they said Biden would work with the other side in a bipartisan manner where he could. But if they prove uncooperative, Biden would take the fight directly to the American people and name check those in the GOP when he does, the advisers said.

Biden's team downplayed the suggestion that his recent missteps on the trail were having an impact, and repeated their belief that voters know who he is, and that they will watch him on the trail and make their own determination on whether his age is an issue.

"I think the biggest mistake we can make in the campaign would be to not let Joe Biden be Joe Biden. People love that he speaks candidly, they know that sometimes he's going to misstate a date or a name or a location. But that's not you know--they also know that they're getting the real deal from him, when they hear from him," a senior advisor said.

ABC News' Mary Bruce and Molly Nagle contributed to this report.

5:29 p.m. Sen. Elizabeth Warren arrives for the debate

The Massachusetts lawmaker arrives at Texas State University for the debate.

4:47pm Booker 'Doing great'

Sen. Cory Booker says he's "doing great" and still deep in debate preparations according to his press secretary, Sabrina Singh. She said to expect Booker to try to convey how he will "unite" and "heal" the country. Singh said Booker doesn't have any pre-debate rituals, but he "really likes Mountain Dew" and is "crushing those constantly."

4:40 p.m. Trump campaign takes to the skies

The Trump campaign is flying a banner over the location of tonight's Democratic debate.

Read more about that here.

4:29 p.m. Fast Facts: The Debate Stage Tonight

Here are some fast facts about the candidates who will be on the debate stage tonight.

There will be over 177 years of political experience on the debate stage tonight.

1 Vice President: Biden

5 United States Senators: Booker, Harris, Klobuchar, Sanders and Warren

1 United States Representatives: O'Rourke

2 Mayors: Buttigieg and Castro

1 entrepreneur: Yang

Debate stage podium positions (left-right)

Klobuchar, Booker, Buttigieg, Sanders, Biden, Warren, Harris, Yang, O'Rourke, Castro

Oldest candidate - Bernie Sanders (78)

Youngest candidate - Pete Buttigieg (37)

Most political experience - Former VP Joe Biden (46 years)

Least political experience - Andrew Yang

Mayor Pete Buttigieg will be the lone candidate on the stage tonight who has served in the United States military.

And here are some common themes

8 candidates attended law school - Biden, Booker, Castro, Harris, Klobuchar, and Yang

Columbia, Harvard, Stanford and Yale will be represented on the debate stage.

Warren and Klobuchar were both the first female Senators to represent their perspective states.

Castro and O'Rourke both have represented the state of Texas.

Harris, Sanders, and O'Rourke have made campaign appearances to Texas Southern University prior to the ABC debate.

And some Senate themes

Booker, Harris, Klobuchar all serve on the Senate Judiciary committee.

Warren and Sanders both serve on the Senate Health, Education, Labor & Pensions.

Harris and Sanders are on the Senate Budget committee.

ABC News' Kelsey Walsh contributed to this report.

2:15 p.m. Trump on what to expect from tonight's debate

The Trump campaign sent around an email to supporters ahead of Thursday's ABC Democratic primary debate running down "the top things" they are expecting from tonight-with "banning plastic straws" at the top of the list, of course.

"Here's a list of the top things we expect to hear the Democrats debate tonight:

Banning plastic strawsDestroying all fossil fuelsBanning fracking everywhereRaising your taxes to pay for illegal criminalsNo more offshore drilling - taking jobs away from tens of thousands of peopleLight bulb banAnd, no more cheeseburgers!"

The email, which doesn't openly ask for donations, also has a countdown clock for tonight's debate along with familiar messaging from the Trump campaign arguing that the candidates will be trying to prove who's "the BIGGEST SOCIALIST."

ABC News' William Steakin contributed to this report.

1:52pm Biden on 'The Obama-Biden record'

Former Vice President Joe Biden's campaign shared a video on social media ahead of tonight's debate, seemingly to get out in front of any attacks on Former President Barack Obama's record. "The Obama-Biden record. Joe Biden is proud of it, will defend it, protect it, build on it," the video says at the end.

1:19pm - DNC Chair Tom Perez debriefs ahead of the debate

DNC Chair Tom Perez gaggled with reporters after a roundtable with voters from the Houston suburbs. He said about tonight's debate winnowing the field of Democratic candidates:

"If you look at past primaries, This is exactly what happens on the Republican and the Democratic side. I'm very excited about tonight, what I know will happen tonight is we're going to talk about issues. No one's nobody's gonna be talking about hand size tonight. We're going to talk about how we reduce, how we address the gun epidemic, we'lll have a number of victims and family members there. We're going to talk about, again, health care, climate change, we're two years removed from a catastrophic storm. And we got a president who's drawing Alabama In the aftermath of storms."

10 a.m. Gov. Bullock's debate night plans

Montana governor and one-time debate stage attendee Steve Bullock will watch tonight's debate and play bar games with his campaign staffers at the 3-star Yelp rated Tipsy Crow Tavern in Des Moines, Iowa.

Bar games include, but are not limited to, cornhole and a large Connect 4.

While there is no giant Jenga, Tipsy Crow is dog friendly meaning there could be an appearance by the #TeamBullock office dog, Walter the Doodle.

ABC News' Samantha Sergei contributed to this report.

9:15 a.m. Inslee demurs on possible Cabinet position

In an interview that appeared in Heated, a new climate newsletter from New Republic contributor Emily Atkin, Former Washington State Gov. Inslee says he isn't seeking a position in a Democratic administration and more on the candidates' adopting some of his climate plans and what he hopes to see tonight. He is a former presidential candidate who advocated unsuccessfully for the Democratic National Committee to hold a climate change-themed debate.

ABC News' Stephanie Ebbs contributed to this report.

9 a.m. Here's how to watch the ABC News debate

The debate will be held at Texas Southern University, a public, historically black university, and will air from 8 to 11 p.m. ET across ABC, on Univision with a Spanish translation, locally on KTRK-TV and on ABC News Live. The streaming channel is available on the ABCNews.com, Good Morning America and FiveThirtyEight websites and mobile phone apps, as well as on Hulu Live, The Roku Channel, Facebook Watch, AppleTV, Amazon Fire TV, YouTube, Apple News, and Twitter.

And here's how to watch the debate in Spanish

Podrás seguir el evento en vivo y en español a través de las pantallas de Univision y las plataformas digitales de Univision Noticias, como Facebook, YouTube y Periscope. Además el minuto a minuto de lo que sucede en el debate en nuestro live blog en UnivisionNoticias.com.

8:10 a.m. FiveThirtyEight and Ipsos get down and dirty with the digits

FiveThirtyEight is partnering with Ipsos to poll voters before and after the candidates take the stage tonight.

Check out the "before" picture, with who voters are considering voting for, which candidates they think are most electable and more. But by Friday - same url, going live at 1 p.m. EDT -- we'll have the "after" polling, showing who voters thought had the best (and worst) debate, who increased (and lost) support, whose electability ratings improved (or worsened) and more!

Also check out their ...

Debate preview chat

And debate preview podcast

4 am Here's your cheat sheet to the ABC News debate

The winnowing presidential primary field is five months out from the first ballots being cast - but Democrats all vying for the top of the ticket are still carving out their own paths to defeat President Donald Trump.

Those differing routes are never more apparent than when standing shoulder-to-shoulder on a debate stage.

"You know, we have a president, as everybody has acknowledged here, every day is ripping at the social fabric of this country, but no one man has the capacity to rip that apart," former Vice President Joe Biden said in his opening pitch at the second Democratic debate. "It's too strong. We're too good ... Mr. President, this is America. And we are stronger and great because of this diversity, Mr. President, not in spite of it."

"Our problems didn't start with Donald Trump," Massachusetts Sen. Elizabeth Warren told the crowd at the same debate one night prior, as she articulated her theme of striving for bold reforms. "Donald Trump is part of a corrupt, rigged system ... We're not going to solve the urgent problems that we face with small ideas and spinelessness. We're going to solve them by being the Democratic party of big structural change."

For the first time, the lineup includes polling front-runner Biden sandwiched in between Warren and Vermont Sen. Bernie Sanders, pitting "Middle Class Joe" against the leading progressives.

But as the former vice president relies on winning back the voters that propelled the first African-American president, Barack Obama, to the White House, liberals Sanders and Warren are running a different kind of race, seeking to forge their own coalition to capture the party's presidential nomination.

Much like in 2008, the 2020 contest could see a state-by-state battle for the nomination -- with each caucus and primary bringing a different front-runner and resetting the path to victory.

The divisions in the candidates' strategies were made clear at the second debates in Detroit, when several Democrats took aim at Obama's presidency -- both directly and indirectly -- and the very legacy Biden is running to extend.

Rehashing the Obama legacy

Despite the former president being the party's most popular member, the more liberal flanks and some lower-polling candidates forced Biden to fend off the attacks on his former boss, particularly on health care and immigration.

"Right now we have a dysfunctional health care system. Eighty-seven million uninsured or underinsured, 500,000 Americans every year going bankrupt because of medical bills, 30,000 people dying while the health care industry makes tens of billions of dollars in profit," said Sanders, who along with Warren spent a large portion of their time vigorously defending Medicare for All.

"Medicare for All will fix that and that's why I'll fight for it," said Warren about the legislation introduced by Sanders and seen by some as a more comprehensive replacement for Obama's signature piece of legislation, the Affordable Care Act.

"The reality is that our plan will bring health care to all Americans under a Medicare for All system," said California Sen. Kamala Harris, defending her plan which is more of a hybrid health insurance system that allows private companies to be able to offer health insurance plans within the Medicare system for consumers. "Your plan by contrast leaves out almost 10 million Americans," she said of the Sanders.

On immigration, although the previous White House took steps to overhaul the immigration system -- even using executive powers to protect Dreamers -- several 2020 Democrats took aim at the three million deportations under the Obama presidency, leaving Biden as the sole navigator of those criticisms.

At one point, Booker interrupted the elder statesman: "You invoke President Obama more than anybody in this campaign. You can't do it when it's convenient and then dodge it when it's not."

Former Housing and Urban Development Secretary Julián Castro, too, challenged Biden over Obama-era immigration policies on that stage, without using Obama's name.

"Mr. Vice President, it looks like one of us has learned the lessons of the past and one of us hasn't," said Castro, who served under Obama. "My immigration plan would also fix the broken legal immigration system because we do have a problem with that."

Biden responded by calling out his fellow Democrats for unleashing friendly fire against Obama instead of railing against Trump.

"To compare him to Donald Trump, I think is absolutely bizarre," Biden said at one point during the July debate.

South Bend, Ind., Mayor Pete Buttigieg echoed Biden's sentiment to reporters in Las Vegas days after the debate, saying, "[I'm] a little puzzled that when we're all running against President Trump, some folks felt the need to run against President Obama."

Even the president saw the last debate as more of a disavowing of Obama than of himself.

At a rally in Cincinnati following the second round of debates, Trump called out his Democratic rivals for unleashing on his predecessor, telling the crowd, "The Democrats spent more time attacking Barack Obama than they did attacking me practically."

Those who took aim at parts of Obama's record -- either by backing Medicare for All over Obamacare or by rejecting certain aspects of his immigration agenda -- might run into a tougher road ahead as they seek to win back those voters who drifted from Democrats and turned to Trump.

Finding a lane in a still crowded primary

At this next debate, the contenders outside of the top tier -- standing on the edge of the stage and in need of a breakthrough -- will likely be trained on finding their lane by giving Democratic primary voters more than just a return to the pre-Trump era (like what Warren and Sanders are pitching), without alienating moderates or disapproving of the Obama legacy (which Biden is campaigning on).

For some in the field hoping to pick up voters that might stray from the 76-year old Biden, that middle ground oftentimes reflects a message of "generational change," "unity" and rising above the divisiveness.

Buttigieg, who touts a refrain fueled with urgency, said over the weekend in New Hampshire, "None of us can afford to wait to act on our current problems, because they're becoming a crisis ... It's not enough to think up a good policy. We have to unify Americans around these solutions or nothing will actually get done."

"The purpose of the presidency is not the glorification of the president, but the unification of the people," he added.

Harris invokes her prosecutorial past and compelling backstory to appeal to a broad coalition -- often telling voters as she did in the last debate, "I come from fighters ... My sister Maya and I joke we grew up surrounded by a bunch of adults that marched about this thing called 'justice.' And I'm prepared to march with you, to fight with you for the best of who we are, and to successfully prosecute the case against four more years of Donald Trump."

"I'm going to make sure the American people know about my strong, compelling vision for the future of our country. I believe that I can bring our country together, that we can reunite the old Obama coalition and then take that to the next level," Castro, who frequently pushes for a fairer system to even the playing field, said in Beaufort, South Carolina last month.

Booker, who is looking to assemble support by inspiring his audience, told the New Hampshire Democratic Party state convention over the weekend: "Beating Donald Trump is the floor it is not the ceiling. Beating Donald Trump gets out of the valley, but it does not get us to the mountaintop. I want to go to the mountaintop."

Former Texas Congressman Beto O'Rourke, newly impassioned by a mass shooting in his native El Paso that killed 22 people last month, is on an unvarnished quest to fill the void in moral leadership he sees in the era of Trump.

"Though we're connected to a president with no values and no morals, we're also connected as a people by our ambitions and aspirations," he told reporters over the weekend, later admitting that he might swear on the debate stage. "Democrats, Republicans, independents, before any of those things, we are Americans first and need to start treating each other like it."

Minnesota Sen. Amy Klobuchar, who traded few barbs at the previous two debates while focusing on her roots in the Midwest -- and her ability to work across the aisle -- seeks to restore dignity to the presidency for "all of America."

"I don't want to be the president for half of America, I want to be the president for all of America," she said Saturday after her speech to the New Hampshire Democratic Party.

For entrepreneur Andrew Yang, who is carving out his own base in the shape of an eclectic cult-like following, the debate stage is an opportunity to attract a wide swath of voters, across the ideological spectrum, as his substantive campaign seeks to make the masses "think harder."

"We automated away 4 million manufacturing jobs in Michigan, Ohio, Pennsylvania, Wisconsin. If those states sound familiar, those are all the swing states that Donald Trump needed to win and did win. So to me this was a straight automation story that immigrants are being scapegoated for economic problems they have little to nothing to do with ... It's not immigration, it's automation," he said in a recent interview with CBS This Morning.

In store this time around will be opportunities for the contenders to hash out differences that first drew sparks in the earlier rounds and across different stages.

The main event

But the main show will be at center stage, where Biden and Warren will face off side-by-side, as she continues to narrow the gap between them in recent polling. In an ABC News/Washington Post poll out this week, the former Harvard professor saw a six-point gain from June.

Biden argued at a campaign stop in Laconia, New Hampshire on Friday that sharing the stage "will be a good thing" because he says, "I've never had to break through."

Warren, too, appeared to dismiss a potential clash with Biden, telling ABC News it does "not really" change her approach.

"The way I see this is, this is a chance to talk to people all across the country, about how we've got a government that works great for the wealthy and the well connected, just not working for everyone else. And we got a chance to change that in 2020," she said.

While all eyes seem to be on the moderate vs. progressive showdown between the two, an advisor for Biden suggested that he will be ready to take on Warren's "I have a plan for that" mantra -- saying Biden's plans were anything but middle of the road.

"I expect you'll see Biden echo an important point he made during last week's climate forum: We need more than plans, we need a president who can deliver progress on the most pressing issues facing Americans, which Joe Biden has proven he can throughout his career," the official told ABC News.

ABC News' John Verhovek and Molly Nagle contributed to this report.