NEW YORK --From Iowa to New Hampshire - on the air, on the bus and on the stump - candidates vying to become America's next president roared out of the holidays in full force Monday with less than a month to go before voting begins.
The coming weeks are especially crucial for Republicans as voters look to weed through the thicket of choices to determine who will represent and attempt to reunite a bickering party. This, as contentious issues over terrorism, security, civil liberties and gun ownership reverberate, giving candidates plenty to argue about.
Democrat Hillary Clinton and Republican Donald Trump have been the consistent favorites in polls overall. But they are not equal in that regard.
Clinton also has an impressive organization behind her while Trump's ability to pull off a winning ground game is in question and his frugal spending to date has stood in stark contrast to his vast personal wealth. He says he's opening the money spigot now.
Early voting is often deemed critical in races, like this one, when the path to a nomination is so unclear. As mystery shrouds the Republican race, the Democratic one hangs on whether Bernie Sanders, an independent socialist senator from Vermont, can turn his months of large, passionate rallies into enough votes to upset the former first lady.
In Iowa, the first of the early voting states, Republican contender Ted Cruz was set to launch his bus tour through the state where his campaign feels he is well-positioned to win.
Cruz called on Iowa voters to bring nine of their friends and family members with them to vote for him in the Feb. 1 caucuses. Cruz made the plea Monday in the first of 28 planned stops in Iowa over the next six days.
"Now is the time that the men and women of Iowa step up and make your decision," Cruz said during his stop in Boone, Iowa.
Second-time Republican hopeful, former Arkansas Gov. Mike Huckabee, also set out in Iowa on Monday, holding breakfast meetings and town halls across the state as he looks to turn his campaign's sluggish start around..
Clinton also kicked off a two-day swing in Iowa, where she was scheduled to attend several organizing events in preparation for the caucuses. In New Hampshire, former President Bill Clinton launched his own tour on behalf of his wife, talking both about Hillary Clinton's campaign promises and his own experience in the White House.
Sanders also campaigned Monday in New Hampshire, which votes Feb. 9.
In 2008, Hillary Clinton suffered a stringing defeat in Iowa, rebounded with a win in New Hampshire and waged a grinding campaign across the country before Barack Obama claimed victory in the nomination race on his way to the presidency.
Trump sought to derail his rivals Monday, debuting his first television ad in both Iowa and New Hampshire, featuring dark images of the San Bernardino, California, shooters, body bags, and images of masked men.
The ad reinforced highly criticized remarks he made last month proposing a temporary ban on Muslims looking to enter the United States, which sparked outrage from Republican and Democratic rivals alike. The comments threatened the party's drive to attract minorities, an effort already complicated by Trump's negativity toward Mexican immigrants.
Trump says he plans to spend at least $2 million per week on television ads in Iowa and New Hampshire overall.
He was heading to Massachusetts late Monday before catching up to many of the other candidates flooding into New Hampshire this week.
New Jersey Gov. Chris Christie's presidential campaign kicked off the new year by hiring several new people in New Hampshire, where his campaign is banking on a strong finish to propel his campaign forward.
Devon Manchester will serve as deputy political director in the state, campaign spokeswoman Samantha Smith said Monday. Manchester previously served in Massachusetts Gov. Charlie Baker's administration and was a regional field director for the Massachusetts Republican Party, according to the campaign.
The addition will boost Christie's paid staff in the state from four to six with just over a month to go before the primary.
Former Florida Gov. Jeb Bush, by contrast, currently has 20 full-time paid staffers in the state and plans to grow that number at least to 40 in coming weeks.
Republican Carly Fiorina also kicked off 2016 in New Hampshire on Monday, contending that Republicans want to see her debate Clinton, "because you know what's going to happen: I'm going to win."
And Marco Rubio criticized his Republican rivals in a New Hampshire speech focused on national security. The Florida senator declined to call them out by name in the Monday morning address, but said some would weaken the nation's military and intelligence programs designed to prevent terrorism.
"They talk tough," Rubio said in prepared remarks, "yet they would strip us of the ability to keep our people safe."