Manchester: New Hampshire voters could dramatically reshape the race for president on Tuesday, boosting insurgent candidates who have connected with a discontented electorate or providing a second wind to establishment figures struggling to build support.

New York businessman Donald Trump, whose scorched-earth speeches have captivated people disillusioned with politics, is positioned to win the Republican primary, according to all public polls, allowing him to rebound after a second-place finish in the Iowa caucuses.

Trump closed off his campaign here before a crowd of thousands in a Manchester arena. “Tomorrow is going to be the beginning,” he declared. “We have to have a great victory.”

But second place — and third place and fourth — is up for grabs in a state known for its large number of independent voters who can remain undecided right up until they approach the ballot box.

A strong showing by Florida Sen. Marco Rubio could reassure members of his party who were rattled by his uneven performance in Saturday night’s debate and help him sap support from rivals.

But a stumble by Rubio, forecast in some late polls, would revive the chances of Ohio Gov. John Kasich, New Jersey Gov. Chris Christie or former Florida Gov. Jeb Bush, who have staked their campaigns on doing well in New Hampshire but have trailed in the polls.

How the primary shakes out could determine whether the field rapidly narrows to a three-person race involving Trump, Texas Sen. Ted Cruz and one candidate more acceptable to the party establishment, or whether mainstream voters will remain divided among multiple White House hopefuls.

On the Democratic side, Hillary Clinton has fought an uphill battle against Bernie Sanders, the senator from neighbouring Vermont who has consistently held large leads in New Hampshire. The contest between the two — once expected to be a coronation for Clinton, the former secretary of State and the favourite for the Democratic establishment — has become increasingly tense since she eked out a narrow victory in the Iowa caucuses last week.

Clinton, who was able to turn the tables on then-Sen. Barack Obama here in 2008 despite lagging 10 percentage points in the polls, launched an all-out effort Monday to see how close her campaign could come to repeating that upset.

Clinton has repeatedly cited her political resume in an attempt to fend off Sanders and rejected his effort to paint her as insufficiently progressive.

“We are well-positioned, if we have the right leadership, to seize the future just like we have in the past,” she said at a Manchester rally. “It won’t happen by wishing for it; it will happen by working for it.”

Sanders, by contrast, spent the final full day of campaigning trying to shake hands and avoid saying anything that might shake up a race he appears to be winning handily.

The septuagenarian senator has enjoyed strong support from young voters, and on Monday he campaigned with Edward Sharpe and the Magnetic Zeros, a popular indie band, and Emily Ratajkowski, the actress and model.

“The reason we are doing well is we are running a different kind of campaign,” Sanders told a crowd in a Manchester theatre. “We are running a very radical campaign because we are telling the American people the truth.”

New Hampshire residents have been deluged with political advertising, with more than 18,000 spots airing on Boston television, which covers the state, from February 1 until Monday morning, according to a tally by the Boston Globe.

The biggest advertisers are Sanders, who is trying to run up a big margin to show his ability to compete with Clinton’s powerful political operation, and Bush, who has struggled to turn his team’s strong fund-raising into actual votes.

Bush and his fellow Republican candidates barnstormed the state Monday in a last-ditch effort to sew up votes, largely sticking to the same themes they’ve hammered throughout the campaign.

Kasich has gained public support in some surveys and is banking on help from volunteers — some of whom have travelled from his home state of Ohio — to ensure a solid turnout in his favour Tuesday.

“We’re going to do great,” he said after a town hall in Plaistow. “Everything is moving our way.”

In a nod toward Republicans’ next primary on Feb. 20 in South Carolina, Kasich added, “We’re very confident that we’ll be eating gumbo and wearing flip flops.”

Like Kasich, Christie has promised to bring stronger leadership to Washington and undo the gridlock that has frustrated the country. He spoke at a Manchester technology company on Monday, where he urged undecided voters to make up their minds and cast ballots for him.

“Tick tock, tick tock!” he joked.

Christie succeeded in knocking Rubio off balance in Saturday night’s debate, criticising him as unprepared to be president and jeering when the Florida senator tried to repeat lines from his regular stump speech.

The debate raised doubts about whether Rubio could build on the momentum from his third-place finish in the Iowa caucuses. He pressed forward on Monday, saying he was the best-positioned candidate to unite the Republican Party and win the general election in November.

“If I’m our nominee, I win,” Rubio said in a Concord bar. “The Democrats know this. They do not want to run against me.”

Cruz, who finished first in the Iowa caucuses, has also targeted Rubio in hopes of stemming any of his momentum among conservative voters. He’s pummeled the Florida senator for once supporting legislation that would have allowed millions of immigrants who are in the country illegally to achieve legal status.