Former US President Donald Trump on Monday won the first Republican presidential contest by an unprecedented margin, with caucusgoers in the Midwestern state of Iowa braving polar temperatures to cast their ballots.

Trump's victory confirms his domination of the party, with the Iowa win showing that his supporters remain loyal despite him facing 91 criminal charges in several cases against him. Some of the charges concern his efforts to overturn the results of the  2020 presidential election.

What were the results of the Iowa caucus?

With almost all of the vote counted, Trump had 51%, easily beating out Florida Governor Ron DeSantis on 21% and former UN Ambassador Nikki Haley on 19%.

Trump has thus easily surpassed Bob Dole's 1988 record margin of 12.8 percentage points for an Iowa Republican caucus victory.

The state result amply backs up results from national polls that have shown Trump, 77, with a massive lead in the contest to become Republican presidential candidate.

Entrepreneur Vivek Ramaswamy, who was also among the contenders for the Republican nominee, has now thrown in the towel after receiving less than 8% of the Iowa vote, endorsing Trump in a speech to his supporters after results became known.  

The caucus had the lowest voter turnout in 25 years, possibly owing to the life-threatening cold and dangerous driving conditions prevailing in the state.

The contest now moves to the northeastern state of New Hampshire, with the second caucus scheduled in eight days' time.

What has been the reaction to the result?

"THANK YOU IOWA, I LOVE YOU ALL!!!" Trump wrote in characteristic upper case on his social media platform, Truth Social, following news of his win.

In a rambling victory speech,  Trump called for national unity.

"I really think this is time now for everybody, the country, to come together," he said.

Democrat President Joe Biden, who would face off in a rematch against Trump in November if the latter clinches the nomination, said the result made it clear that Trump was first in line for the Republican nomination.

"Looks like Donald Trump just won Iowa. He's the clear frontrunner on the other side at this point," Biden said on the messaging platform X, formerly known as Twitter.

Both de Santis, 45, and Haley, 51, remained combative after their defeats in the poll.

"Because of your support, in spite of all of what they threw at us, we got our ticket punched out of Iowa," DeSantis told supporters.

Haley said "When you look at how well we're doing in New Hampshire and in South Carolina and beyond, I can safely say tonight Iowa made this Republican primary a two-person race."

Trump's court cases

Trump's win in Iowa comes a day before he is expected to appear in court in New York for a civil case where he has already been found liable for sexually abusing and defaming the writer E. Jean Carroll.

Last May, a jury found that he had sexually assaulted Carroll in the dressing room of a New York department store in 1996.

Trump is also confronted by a slew of other legal challenges, including being charged with conspiring to overturn the 2020 election and facing allegations of involvement in the January 6, 2021, attack on the Capitol by his supporters.

Those allegations have led to two states — Colorado and Maine —disqualifying Trump from running for the presidency, but both states put their decisions on hold while he appeals the rulings.

tj/lo (Reuters, AFP, AP)