Donald Trump swept to victory Monday in Iowa's caucuses -- the first vote in the US presidential race -- cementing his status as the presumptive Republican standard-bearer to challenge President Joe Biden in November's election.

Donald Trump has won an overwhelming victory in the US’s first election contest of 2024, easily fending off a winnowed field of Republicans in the Iowa caucuses.

The Associated Press called the race for Trump rapidly, while caucus-goers in much of the state were still casting ballots, a sign of the wide lead the former president had in the race.

“We were a great nation three years ago and now we’re a nation in decline,” he said, speaking to fans after the results confirmed his victory. He then recited a litany of promises for a second term, including rampant drilling and giving police officers full immunity.

The heated battle for second place took much longer, with Ron DeSantis edging out Nikki Haley in an upset.

With an estimated 99% of the vote counted, Trump was on 51%, DeSantis 21.2%, and Haley 19.1%. The former president smashed the previous record margin of victory in a competitive Republican presidential race in the state, which stood at 12 percentage points.

The Florida governor DeSantis campaigned in traditional Iowa fashion, visiting all 99 counties, in the hopes that voters there would reward him as they have candidates in the past. Meanwhile Haley, the former South Carolina governor, had been seen as Republicans’ most moderate choice, with a better chance to beat Joe Biden in the general election than the candidates to her right.

DeSantis could see more momentum in his campaign after the surprisingly strong showing, albeit a distant trail to Trump’s commanding lead. “They threw everything but the kitchen sink at us,” he said, speaking to supporters in Des Moines at the end of the night.”

After all the time and funds his campaign poured into Iowa, his performance was still a disappointment. But his candidacy has survived to fight another day. “We’ve got our ticket punched out of Iowa,” DeSantis said.