Pallade Veneta - Republican election race kicks off in frigid Iowa, testing Trump

If the predicted landslide is forthcoming, Trump's grip on the nomination would appear unshakeable, but a sub-par winning margin could open the door to his main rivals Nikki Haley and Ron DeSantis -- currently locked in a battle for distant second.

"I think we are going to have a tremendous night tonight," Trump said in a video posted on social media. "The people are fantastic and I've never seen spirit like they have."

For the first time since he lost his 2020 reelection bid, the former US president -- who is being prosecuted in four criminal cases, ranging from taking top secret documents to trying to overthrow his election loss -- will face voters.

Trump is expected to win the Midwestern state's first-in-the-nation contest handily as he bids to oust Democrat President Joe Biden in November.

But observers have not ruled out a surprisingly strong showing by Haley or DeSantis.

Adding uncertainty, Iowans will have to contend with blizzards and a potential wind chill in some areas of -45 degrees Fahrenheit (-42 degrees Celsius), potentially throttling turnout.

"I'm asking you to go out, brave the cold and support me in the Iowa Caucus," DeSantis posted on X, formerly Twitter. "You will never have an opportunity to have your vote make more of an impact than you will tonight!"

"The biggest question I'm getting right now is: 'Is the caucus still going to take place? There is going to be a polar vortex,'" warned Maci Arjes, part of a student Republican group at the University of Iowa.

Caucuses will begin from around 7:00 pm (0100 GMT Tuesday), when voters gather in schools, libraries and fire stations across the state.

Caucus participants will listen to speeches on behalf of candidates, before writing their preferred name on a piece of paper and submitting their vote.

Trump plans to attend several of the caucuses over the evening, his campaign told AFP.

- Iowa bellwether -

As the first primary contest, Iowa has an outsized impact, often setting momentum and media narratives ahead of the next states in the calendar.

Trump's margin of his victory will be under scrutiny, with anything less than a crushing margin denting the sense of inevitability that he has worked hard to create.

The latest NBC News/Des Moines Register/Mediacom poll put Trump at 48 percent among likely caucus-goers.

Haley, a former UN ambassador and South Carolina governor, surged into second place but was still only at 20 percent, while Florida Governor Ron DeSantis scored 16 percent.

The Republican primary also features a number of low-polling candidates, including biotech entrepreneur Vivek Ramaswamy.

Caucuses are being held by Iowa's Democrats, along with voting by mail until March. That process, however, is all but set, with Biden seeking a second term.

Biden, whose campaign announced Monday that it had raised more than $97 million in the fourth quarter of 2023 and now has a record-breaking war chest of $117 million, faces no serious threat from his two Democratic challengers -- self-help author Marianne Williamson and Minnesota congressman Dean Phillips.

F.Amato--PV