Bernie Sanders entered the 2016 Iowa caucuses as an underdog. Four years later, on the eve of the 2020 contest, Mr Sanders was playing the part of the frontrunner, criss-crossing the Midwestern state to growing crowds of supporters.
On Saturday night, for example, an estimated 3,000 people — most of them young — attended a rally in Cedar Rapids for the 78-year-old Vermont senator, sipping Budweiser at a concert venue there as they listened to another tub-thumping speech from the candidate, followed by a performance from the indie rock band Vampire Weekend.
In a crowded field that includes former vice-president Joe Biden, Massachusetts senator Elizabeth Warren and former South Bend, Indiana, mayor Pete Buttigieg, among others, Mr Sanders is hoping to rally a new cohort to the polls, drawing on his extensive support among young voters.
“If the turnout tomorrow night is low, we are going to lose,” Mr Sanders told supporters at a Des Moines Super Bowl party on Sunday. “If turnout is high, we win.”
Mr Sanders’s more moderate opponents also drew large crowds as they made their closing arguments to Iowa voters. After months — in some cases, years — of campaigning, Monday evening’s caucuses will be the first real electoral signal of who might emerge to challenge President Donald Trump in November.
On Sunday afternoon, more than 2,000 people packed into a high school gym in Des Moines to hear Mr Buttigieg, 38, claim he is “just one day from victory in the Iowa caucuses”.
The crowd repeatedly broke out in chants of “Boot-Edge-Edge” and “I-O-W-A, Mayor Pete all the way!” as Mr Buttigieg added: “I am also here mindful that even at this late hour, there is a lot of folks still making up their minds.”
The Real Clear Politics average of statewide polls shows Mr Sanders in the lead with 24 per cent of the vote, followed by Mr Biden on 20 per cent, Mr Buttigieg on 16 per cent, Ms Warren on 16 per cent and Amy Klobuchar, a Minnesota senator, on 9 per cent.
Yet the race is too close to call because of the complexity of the caucus system — in which voters realign on a second ballot if their first-choice candidate does not command 15 per cent in a given precinct — and voters’ propensity to remain undecided until caucus night.
Support for Bernie Sanders among Iowa caucusgoers, according to Real Clear Politics
Political insiders had eagerly anticipated the publication on Saturday night of a poll conducted for the Des Moines Register and CNN. But the closely watched survey was pulled at the last minute, after the Buttigieg campaign raised concerns about its methodology.
Surrogates for Mr Sanders warned supporters that the Democratic establishment would try to wrest the nomination from the Vermont senator once again, playing on grievances from the campaign against Hillary Clinton four years ago. Some of Mr Sanders’s online supporters claimed, without evidence, that the Des Moines Register poll had been pulled because it showed a growing lead for the senator.
Michael Moore, the Democratic activist and film-maker who has endorsed Mr Sanders, told a crowd in Cedar Rapids: “Yes, our main opponent is Donald Trump and the Republicans and all this, but we have a 1 per cent in our party, too. And they think they can buy their way on to the stage,” he said. The remark appeared to be a reference to a recent decision by the Democratic National Committee to change the rules to allow billionaire Michael Bloomberg into the next televised debate.
Mr Sanders, Ms Warren and Ms Klobuchar zipped around the state over the weekend in an effort to make up for the previous week, when they had been stuck in Washington for Mr Trump’s impeachment trial. All three senators returned to Washington on Monday for closing arguments, but were expected to fly back out again in time for the caucus results to be announced.
“I have got to get a week in two days,” Ms Klobuchar told supporters at a women’s club in Cedar Falls on Saturday night, adding jokingly: “I’m not competitive at all. I mean, I didn’t notice that my opponents were running around the state.”
After the trial caused her to miss a planned town hall on Friday evening in Des Moines, Ms Warren made a last-minute trip to a brewery in the state capital later that night. Hundreds of supporters crammed the bar and spilled on to the pavement outside, as her campaign staff removed tables to make room and bartenders announced they had run out of glassware. Ms Warren came to the bar straight from the airport after 10pm, wearing a campaign-branded hoodie and telling voters: “You’ve made me a better candidate. And you’ll make me a president.”
Across the state, voters said they were torn between multiple candidates, some on opposite sides of the spectrum, as they considered who was best poised to take on Mr Trump in November.
Shelby Myers, a community college instructor in Cedar Rapids, said on Saturday she was still weighing the two moderate frontrunners, Mr Biden and Mr Buttigieg, and the more progressive duo of Mr Sanders and Ms Warren.
“Sometimes I think we need a total shake-up like the revolution of Bernie. But then I think maybe not,” said Ms Myers. She sighed. “And then I’m back to my four.”
Heidi Berkenbosch, 62, from Prairie City, said that after much deliberation, she decided this week to caucus for Ms Warren, who she described as the most electable candidate.
“It’s not just who do I like, it’s who do other people like enough that they might get elected,” Ms Berkenbosch said. But she added that she might change her mind on caucus night: “If a whole bunch of people are going to somebody else, then I might think maybe that person is more electable.”