Tuesday's primary follows last week's Iowa caucuses where Texas Sen. Ted Cruz had a clear win and Democrat Hillary Clinton barely edged out Sanders. A cluster of big questions could be answered once the results roll in later Tuesday after a week of frenzied campaigning.  Trump is in for a nervous day as he waits to see whether he can turn support at huge rallies into votes after falling short of his polling numbers in Iowa last week.  Marco Rubio's stumble under New Jersey Gov. Chris Christie's ferocious fire at Saturday's GOP debate, meanwhile, threatens to stall his momentum heading into New Hampshire, where the Florida senator looked likely to emerge as the top establishment candidate.  As he left a polling station in Derry, New Hampshire, Tuesday, Rubio dismissed concerns about his debate performance as a "media thing."  "Voters in New Hampshire are serious about, they understand what's at stake here," Rubio told CNN's Dana Bash. "The future of America is at stake."  Nightcap: Final hours in New Hampshire: Clintons stand by Sanders hits | Sign up  For their part, Democrats are waiting to assess the magnitude of Sanders' expected victory over Clinton, which could offer the anti-Wall Street crusader a boost heading into less hospitable territory in southern states.  Campaigning for the primary drew to a close Monday with Trump and former Florida Gov. Jeb Bush trading deeply personal taunts and Rubio trying to bounce back from his tough debate night.  The latest CNN/WMUR daily tracking poll on Monday showed Sanders with a 26-point lead over Clinton. On the Republican side, Trump maintained the lead he has held for months, 31% to next-best Florida Sen. Rubio with 17%. Three-quarters of the polling was completed before Saturday's debate, so it was unclear whether Rubio had been hurt by his rocky performance.  Among other candidates, Cruz was third with 14%, ahead of Ohio Gov. John Kasich at 10% and former Florida Gov. Jeb Bush at 7%. Christie received 4%, according to CNN's tracking poll. The survey has a margin of error of plus or minus 5.2 percentage points. The high number of undecided voters could make this a very fluid race.  Despite his lowly position in the polls, Christie has spent the past few days basking in his debate assault on Rubio.  Under pressure from the New Jersey brawler, Rubio repeated the same line four times during the debate, exacerbating criticisms that he is overly scripted.  "When the lights get that bright, you either shine or you melt, and we can't afford to have a president who melts," Christie said Monday at a campaign event in Hudson, New Hampshire.  Christie, Bush and Kasich are hoping that Rubio's rough night halts momentum he built up coming third in Iowa. A strong second place in the Granite State would enhance Rubio's case that he is best-positioned to consolidate opposition to Trump and Cruz.  READ: Donald Trump or Bernie Sanders? Some voters can't decide  Trump, for his part, hinted Sunday that he understands how crucial New Hampshire is to his campaign.  "I could say to you if I came in second and third I'd be thrilled, okay? I know all about expectations," Trump told Bash on Sunday. "If I came in second I wouldn't be happy, okay?"  READ: Trump repeats vulgar word audience member uses to describe Cruz  Bush, who for once equaled or even got the better of Trump on the debate stage on Saturday, has been mounting a last stand in New Hampshire and on Monday lashed out at the former reality TV star on Twitter.  "You aren't just a loser, you are a liar and a whiner," Bush wrote in an apparent reference to Trump's claims of irregularities in the Iowa caucus results.  Trump had a scathing response in an interview with CNN's Wolf Blitzer: "He's a stiff. He's not a guy that can be president. He doesn't have what it takes."  He continued: "He's a desperate person. He's a sad and, you know, he's a pathetic person. He doesn't even use his last name in his ads. He's a sad person who has gone absolutely crazy. He's a nervous wreck."  Find your presidential match with the 2016 Candidate Matchmaker  The Democratic race between Clinton and Sanders also got testy, with a clash over the former New York senator's ties to Wall Street and her campaign's attacks on his foreign policy.  On Sunday, Bill Clinton slammed the Vermont senator's supporters who he said subjected opponents to "vicious trolling and attacks that are literally too profane often -- not to mention sexist -- to repeat."  Only hours from the primary, new clouds gathered around the Clinton campaign following a Politico report that the candidate and her husband were disappointed with the direction of her campaign and that a staff shakeup could be in the offing.  But Clinton campaign chairman John Podesta dismissed the report.  "There is zero truth to what you may be reading. It's wrong. Hillary stands behind her team, period," he wrote on Twitter.  Clinton, after a campaign stop in Manchester, responded to the reports of a campaign shakeup in an interview on MSNBC's "The Rachel Maddow Show" Monday, acknowledging her campaign will "take stock" of their operation.  "I have no idea what they're talking about or who they are talking to," Clinton said of the Politico report. "We're going to take stock, but it's going to be the campaign that I've got. I'm very confident in the people that I have. I'm very committed to them, they're committed to doing the best we can."  David Axelrod, a CNN senior political commentator and former top adviser to President Barack Obama, suggested that the blame lies at the top.  "When the exact same problems crop up in separate campaigns, with different staff, at what point do the principals say, 'Hey, maybe it's US?'" Axelrod tweeted.
New Hampshire voters will make their choice for president in the first-in-the-nation primary contest that public opinion polls suggest could deliver victory to a pair of outsider candidates, Republican Donald Trump and Democrat Bernie Sanders.