Public Advocate Bill de Blasio, City Council Speaker Christine Quinn, Former Congressman Anthony Weiner, ex-comptroller Bill Thompson and current Comptroller John Liu squared off on a variety of topics, including the NYPD's stop-and-frisk program, the future police commissioner and how to fix education.
The first question of the debate focused on stop and frisk, which a judge on Monday ruled violated Constitutional rights.
"I'm the only person on this stage, that will lead the effort to override [Bloomberg's veto]," Quinn said.
The Speaker then went on the attack against Bill de Blasio for saying he would fire Commissioner Ray Kelly only to hire one of his deputies.
"[Kelly] has done good things for the city of New York, but has also become the face of this abusive stop-and-frisk policy," countered de Blasio, the new front-runner in the most recent poll.
De Blasio opened the debate by saying there was a tale of two cities in New York, pledging a tax on the city's superwealthy residents. Later, he said the City can't "continue the policies of Mayor Bloomberg and Speaker Quinn," but must move for progressive change.
In making her case to be mayor, Quinn argue, "You know I can do it because I'm the only one on the stage with a proven record of results."
Anthony Weiner acknowledged personal mistakes and apologized again when faced with a question about why voters should trust him after learning the sexting that got him in trouble in Congress continued after he resigned in disgrace.
"If you want to talk about my personal failings, they've been all over the papers. But, if you want someone who is going to stand up in the face of pressure, someone who is going to take on the Republicans at every turn, someone who has good ideas and who is willing to stand up for those good ideas, I'm the person who you want to vote for," he argued.
Weiner's opponents largely declined to address the matter.
"We should not be talking about one individual and their personal life," de Blasio said.
Weiner tried to turn the tables on the issue, saying he has "owed up to his personal failings," but Quinn hasn't explained about her failings as a leader and lawmaker.
"Nobody on stage and nobody in New York should be lectured by Anthony Weiner about what we need to apologize for tonight," Quinn fired back.
Quinn came under fire for supporting Mayor Michael Bloomberg's campaign for a third term in 2009.
"Under that reasoning that we did it because of the financial situation, we changed a President in 2008. We had a new President. We elected him. By that venture, we should have suspended that election also," Bill Thompson said. "Speaker Quinn betrayed the people of New York and undermined democracy, and that's a fact."
On the matter of education and recent low state test scores among New York City students, the candidates seemed to agree that the results were a wake-up call.
"The results were horrendous for Mayor Bloomberg and the Department of Education, but they were even moreso for the million school kids in our public schools," John Liu said. "So much of their years are spent getting ready for the test. It has to stop. We have to restore the learning environment in each and every one of our schools."
De Blasio called a stronger focus on early education and pre-k.
"If we don't lay that foundation, our children won't be able to achieve at the level necessary," he said.
Thompson said he would stop Bloomberg's "policy of closing schools." Quinn said she would close failing schools only as a last resort.
Tuesday's debate comes with less than a month remaining until the Sept. 10 primary.
A new poll released Tuesday shows Bill de Blasio has taken over the lead among Democratic candidates in the mayoral race.
A Quinnipiac University poll released on Tuesday shows de Blasio is the new front-runner with the support of 30 percent of voters surveyed.
Quinn has 24 percent, with 22 percent for former Comptroller William Thompson, 10 percent for Weiner, 6 percent for Comptroller John Liu, 1 percent for former Council member Sal Albanese and 7 percent undecided.
If no candidate reaches 40 percent of the vote at the primary, the top two advance to a runoff three weeks later.