Democrats are hoping that voters in New Hampshire will reset the party’s presidential nomination fight and bring clarity to a primary season that has been marred by deep dysfunction and doubt.

Since the chaotic Iowa caucuses failed to perform their traditional function of narrowing the race, it now falls to New Hampshire to begin culling the Democratic field, which still features almost a dozen candidates.

For Vermont senator Bernie Sanders, the vote is an opportunity to lock in dominance of the party’s left flank.

A repeat of his strong showing in Iowa could severely damage progressive rival Massachusetts senator Elizabeth Warren, who faces the prospect of an embarrassing defeat on her near-home turf.

Democratic presidential candidate Bernie Sanders gestures during a campaign stop at Franklin Pierce University in Rindge, New Hampshire
Bernie Sanders during a campaign stop at Franklin Pierce University in Rindge, New Hampshire (Charles Krupa/AP)

While Mr Sanders marches forward, moderates are struggling to unite behind a candidate.

After essentially tying with Mr Sanders for first place in Iowa, Pete Buttigieg, the 38-year-old former mayor of South Bend, Indiana, begins the day as the centrist frontrunner.

But at least two other White House hopefuls – former vice president Joe Biden and Minnesota senator Amy Klobuchar – are competing for the same voters, a dynamic that could delay the nomination contest if it continues.

More than a year after Democrats began announcing their presidential candidacies, they are struggling to coalesce behind a message or a messenger in their desperate quest to defeat President Donald Trump.

That is raising the stakes of the New Hampshire primary as voters weigh up whether candidates are too liberal, too moderate or too inexperienced – vulnerabilities that could play to Mr Trump’s advantage in the autumn.

During the final day of campaigning, many voters said they had still not made a final choice.

US presidential election 2020 key dates
(PA Graphics)

University of New Hampshire pollster Andy Smith predicted that as many as 20% of voters would make up their mind on Election Day, with twice as many deciding over the last three days.

“Historically, New Hampshire is known to shift late,” he warned those with expectations.

New Hampshire’s secretary of state predicted record-high turnout on Tuesday.

If that does not happen, Democrats will confront the prospect of waning enthusiasm following weak turnout in Iowa last week and Mr Trump’s rising poll numbers.

Another complication that could affect the turnout is the weather.

Forecasts are for a light wintry mix of rain and snow in some parts of the state, which could make travel treacherous.

Mr Biden – and the Democratic Party’s establishment wing – may have the most to lose on Tuesday should the former two-term vice president underperform in a second consecutive primary election.

Democratic presidential candidate Joe Biden flexes his arm along with Jaime Karnilaw of Concord, New Hampshire
Joe Biden flexes his arm along with Jaime Karnilaw of Concord, New Hampshire (Andrew Harnik/AP)

He has earned the overwhelming share of endorsements from elected officials across the nation as party leaders seek a relatively “safe” nominee to run against Mr Trump.

But the distance between Democratic voters and their party leaders appears to be growing.

After finishing in a distant fourth place in Iowa, Mr Biden acknowledged he would be likely to “take a hit” in New Hampshire.

His campaign sought to cast New Hampshire as one small step in the path to the presidential nomination, with contests coming up soon in more diverse states that award more delegates such as Nevada and South Carolina, where Mr Biden hopes to retain his advantage among minority voters.

The stakes were high for Ms Warren as well in a contest set next door to her Massachusetts home.

Democratic presidential candidate Elizabeth Warren speaks at a town hall campaign event in Portsmouth, New Hampshire
Elizabeth Warren at a town hall campaign event in Portsmouth, New Hampshire (Robert F Bukaty/AP)

She has positioned herself as a mainstream alternative to Mr Sanders but is suddenly looking up at him and Mr Buttigieg as Ms Klobuchar fights to peel away female support.

Ms Warren sought to project confidence, telling reporters she has “been counted down and out for much of my life”.

“You get knocked down,” she said.

“You get back up.”

Mr Buttigieg, young and with no governing experience beyond the mayor’s office, is trying to emerge as the leading Biden alternative for his party’s moderate wing.

His team – with 75 paid staff, 15 campaign offices scattered across 10 counties and roughly 300 trained volunteers heading the get-out-the-vote teams – has added volunteers since Iowa, aides said.

Democratic presidential candidate Pete Buttigieg during a campaign event in Milford, New Hampshire
Pete Buttigieg during a campaign event in Milford, New Hampshire (Matt Rourke/AP)

Mr Buttigieg has aggressively courted moderate Democrats, independents and what he calls “future former Republicans” as he tries to cobble together a winning coalition, just as he did in Iowa, where he finished in a near tie with Mr Sanders for the lead.

Kim Holman was one of 1,800 people who crowded into Elm Street Junior High School’s gym in Nashua over the weekend.

She calls herself “super torn”.

“I’m still kind of on the fence. I love Pete’s energy and his passion,” the 52-year-old personal trainer said.

“It does make me a little nervous he’s so new to politics.”