Donald Trump has muscled past his rivals to capture the first 2024 Republican presidential contest in Iowa, once more asserting his dominance over the party as he seeks a third consecutive nomination.
"We want to thank the great people of Iowa. Thank you," Trump said while speaking from his campaign headquarters in Des Moines, Iowa.
He added: "I really think this is time now for everybody, our country, to come together."
Florida Governor Ron DeSantis finished well behind in second place, Edison Research projected, edging out former as they battle to emerge as the chief alternative to Trump.
"We are all having a good time together," Trump said when referring to DeSantis and Haley, drawing laughter from the crowd.
"I think they both actually did very well, I really do."
Major United States networks took just 30 minutes to project the winner, with Trump opening up an unprecedented 32-point lead over second-placed DeSantis over the following hour or so.
Trump was poised to win by an unprecedented margin for an Iowa Republican contest, strengthening his case that his nomination is a foregone conclusion given his massive lead in national polls even though he faces .
With nearly 90 per cent of the expected vote tallied, Trump had 50.9 per cent, while DeSantis was at 21.4 per cent and Haley 19.0 per cent, according to Edison. The largest margin of victory for an Iowa Republican caucus had been 12.8 percentage points for Bob Dole in 1988.
Entrepreneur Vivek Ramaswamy ended his long-shot presidential bid after earning just under 8 per cent of the vote on Monday and endorsed Trump in a speech to supporters.
Vivek Ramaswamy dropped out of the race for the Republican presidential nomination following Donald Trump's win at the Iowa caucuses. Source: AAP, SIPA USA / USA Today Network
Both DeSantis and Haley had been aiming for a strong second-place finish to convince donors and supporters that their challenges to Trump remain viable.
DeSantis in particular had wagered his campaign on Iowa, barnstorming all of its 99 counties, and a third-place finish could increase pressure for him to end his bid.
Donald Trump appeared likely to win the Iowa caucuses by a record-setting margin, based on early results. Source: Getty, AFP / Christian Monterrosa
"We've got our ticket punched out of Iowa!" DeSantis told supporters in West Des Moines on Monday.
Republicans in more moderate New Hampshire will choose their nominee eight days from now. Polls show Trump with a smaller lead over Haley there, with DeSantis far behind.
Iowans braved life-threatening temperatures to gather at more than 1,600 schools, community centres, and other sites for the state's first-in-the-nation caucus, as the 2024 presidential campaign officially got underway after months of debates, rallies, and advertisements.
Caucus-goers appeared broadly supportive of Trump, according to an Edison Research entrance poll.
Supporters of former US President and Republican presidential hopeful Donald Trump celebrate at a watch party during the 2024 Iowa Republican presidential caucuses in Des Moines, Iowa, on Monday. Source: Getty, AFP / Jim Watson
"Trump is very narcissistic, he's very cocky, but he's going to get stuff done," said Rita Stone, 53, a Trump backer, who attended a caucus at a West Des Moines high school. Like many other voters, Stone said her leading concern was the US southern border with Mexico, praising Trump's effort to build a wall when he was president.
Trump has aimed to create an air of inevitability around his campaign, skipping all five of the Republican debates thus far and largely eschewing the county-by-county politicking that most candidates do ahead of the Iowa vote.
Iowa Democrats did not vote on Monday for their presidential nominees because the party has reshuffled its nominating calendar to put states with more diverse populations ahead of Iowa this year. They will cast their ballots by mail, with the results to be released in March.
Iowa has historically played an outsized role in presidential campaigns due to its early spot on the campaign calendar.
But the winner of Iowa's Republican caucuses did not go on to secure the nomination in the last three competitive contests in 2008, 2012, and 2016.
A political battleground that backed Democrat Barack Obama in 2008 and 2012, the state is now seen as reliably Republican in presidential elections as registered Republicans edge out Democrats.
