Democratic presidential candidates are trying to make a last appeal to those in Iowa struggling to make a final decision about who to back for the party’s presidential nomination.
Speaking to several hundred supporters in Cedar Rapids on Sunday, Senator Bernie Sanders declared “we are the campaign of energy and excitement” and said “we are in a position to win tomorrow night”.
Pete Buttigieg, the 38-year-old former mayor of South Bend, Indiana, talked up his newcomer status, telling a rally in Coralville that when Democrats have won the White House in the past, “we have done it with someone who is new in national politics”.
What will happen in November begins tomorrow. pic.twitter.com/v0GeazyV6y— Pete Buttigieg (@PeteButtigieg) February 3, 2020
But former Vice President Joe Biden, emphasising his decades of Washington experience, told voters there was no time for “on-the-job training”.
Massachusetts Senator Elizabeth Warren pressed her supporters to “fight back” if they ever lose hope.
The Iowa caucus is the effective starting gun for actual voters to get involved in the process that will determine Donald Trump’s opponent in November’s presidential election.
The Democratic race is unusually large and jumbled heading into Monday’s caucus.
Four candidates were locked in a fight for victory in Iowa; others were in position to pull off surprisingly strong finishes.
“This is going to go right down to the last second,” said Symone Sanders, a senior adviser to Mr Biden’s campaign.
Polls show Mr Biden in a close race in Iowa with Mr Sanders, Ms Warren and Mr Buttigieg.
Minnesota Senator Amy Klobuchar and tech entrepreneur Andrew Yang are also competing aggressively in the state.
Democrats’ deep disdain for Mr Trump has put many in the party on edge about the decision.
A series of external forces has also heightened the sense of unpredictability in Iowa, including Mr Trump’s impeachment trial in the Senate, which marooned Ms Warren, Mr Sanders and Ms Klobuchar in Washington for much of the past week.
Many campaigns were looking to a final weekend poll to provide some measure of clarity.
But late Saturday night, CNN and The Des Moines Register opted not to release the survey because of worries the results may have been compromised.
New caucus rules have also left the campaigns working in overdrive to set expectations before the contest.
For the first time, the Iowa Democratic Party will release three sets of results: who voters align with at the start of the night; who they pick after voters supporting nonviable candidates get to make a second choice; and the number of state delegate equivalents each candidate gets.
The new rules were mandated by the Democratic National Committee as part of a package of changes sought by Mr Sanders following his loss to Hillary Clinton in the 2016 presidential primaries.
The revisions were designed to make the caucus system more transparent and to make sure that even the lowest-performing candidates get credit for all the votes they receive.
But party officials in Iowa and at the DNC have privately expressed concerns in recent weeks that not just Mr Sanders but multiple campaigns will spin the results in their favour, potentially creating chaos on caucus night.
We view Iowa as the beginning, not the endSymone Sanders, aide to Joe Biden
Mr Biden’s campaign appeared to be trying to lower Iowa expectations, cautioning against reading too much into Monday’s results.
Mr Biden is hoping to sustain enough enthusiasm and money coming out of Iowa to make it to more diverse states where he hopes to draw strong support from black voters.
His campaign is particularly focused on South Carolina, the fourth state on the primary schedule.
“We view Iowa as the beginning, not the end,” Symone Sanders, a Biden senior adviser, said at a Bloomberg News breakfast.
“It would be a gross mistake on the part of reporters, voters or anyone else to view whatever happens on Monday – we think it’s going to be close, but view whatever happens — as the end and not give credence and space for New Hampshire, Nevada, and South Carolina.”
Mr Sanders, Ms Warren and Ms Klobuchar fanned out across the state, trying to make up ground after missing most of the last two weeks of campaigning due to the Senate impeachment trial.
In a conference room in Cedar Rapids, Ms Klobuchar appealed to caucus-goers by asking them to think about the voters who will not be caucusing — moderate Republicans, voters who swung from Barack Obama to Mr Trump and voters who stayed home in 2016.
“They’re watching all of this right now,” Ms Klobuchar said.
“We have people who want to come with us. And we need a candidate who is going to bring them with us instead of shutting them out.”
Ms Klobuchar retold her joke about slowly winning over former Cedar Rapids Mayor Kay Halloran, who once told Ms Klobuchar that she was “78% with you”.
“We don’t have time for that!” Ms Klobuchar said.
“She got to 100% and so can you.”