Donald Trump was given his first election victory of 2020 on Monday as the Iowa Republican Party said he had won its caucus by a landslide.

Trump got 97.1 per cent of the vote, with his two opponents, Bill Weld and Joe Walsh getting just 1.3 and 1.1% with 0.5% split between 'other' candidates and with a handful precincts yet to report.

The result was hardly a surprise, but the Trump team had sent his two adult sons and other senior figures to the state in a dry run for the presidential elections.

Iowa was one of the states which had not suspended their mechanism for choosing a Republican candidate, so that it could keep its first in the nation status.

That gave the Trump campaign a chance to practice its 'ground game,' although in reality, there was no real opposition.

Your browser does not support iframes.

Trump 2020: A landslide in Iowa is hardly a surprise, but the president's campaign used it as a dry run for the real re-election campaign later this year

Quixotic campaigns: Former Tea Party firebrand turned fervent anti-Trump Republican Joe Walsh got 1.4% of the votes, and former Massachusetts governor Bill Weld came in on 1.5%

Guess who I voted for: In Garnavillo, Clayton County, it was clear who was backing Trump -and across the entire county, just six people didn't while 214 voted for him

Top of the ballot: How Republicans were asked to caucus in Clayton County

Votes are seen during the Republican caucus at Thoma Dairy Bar Cafe in Garnavillo, Iowa, U.S. February 3, 2020. REUTERS/Kamil Krzaczynski

Back where he came in fourth: Ben Carson was one of the high-profile supporters the Trump campaign dispatched to Iowa, where he had been a presidential candidate four years ago

Walsh and Weld have each launched a quixotic campaign bid to unseat Trump with little hope of winning any significant number of votes, seeking backing from a party now in lockstep with the president.

The result is hardly a bellwether for the Trump camp, with turnout a fraction of what it was in 2016, or compared to the Democratic caucuses under way at the same time.

In some counties, there was 100% backing for Trump, including Lyon, Franklin , Emmet and Buena Vista counties all recording no votes against the president.

Iowa had in fact not been a victory ground for Trump in 2016, with Ted Cruz coming out on top by 27.6% to Trump's 24.3%. Marco Rubio was a close third at 23.1%, while Ben Carson came in at 9.3%.

Carson, now HHS Secretary, was back in Iowa for the day, speaking in support of Trump at the Heartland Presbyterian Church in Clive, West Des Moines.

He was one of dozens of senior Trump figures who flew in, led by Donald Trump Jr. and Eric Trump and his wife Lara.

Donald Trump Jr. was among the Trump surrogates who went into campaign mode in Des Moines, with his brother Eric by his side

Also in Iowa: Kimberly Guilfoyle was with her boyfriend Donald Trump Jr. to take part in the Trump campaign practice run for the real re-election campaign

Also speaking was Mick Mulvaney, the acting chief of staff who has not been seen speaking in public since he held a press briefing at the White House and said of holding aid to Ukraine, 'get over it, we do it all the time.'

Iowa's decision to press ahead with its caucus is in line with most states - although some have cancelled their contests.

Among those which will not have a contest are Kansas, Nevada, South Carolina, Arizona, Alaska, Virginia, Nevada and Hawaii.

Cancelling primaries is in line with both parties' practice when an incumbent is seeking re-election; in recent years it has been done by Democrats for Barack Obama and Bill Clinton, and Republicans for both the Bushes.

Both Gerald Ford and Jimmy Carter were hit with grueling primary challenges and went on to lose; in Ford's case he had become president through the resignation of both Richard Nixon and Spiro Agnew as vice president.

Trump's challengers have however failed to reach the support which Ronald Reagan achieved against Ford, whom he came close to toppling from the party's nomination, and Edward Kennedy gathered against Jimmy Carter, in a contest which went to the 1980 Democratic convention.

Walsh, 58, was a firebrand Tea Party supporter who became notorious for shouting 'you lie!' at Barack Obama during a State of the Union address in 2009, during Walsh's one term in Congress.

But he is now an outspoken anti-Trump Republican and has publicly repented many of his previous positions.

Weld, 74, was governor of Massachusetts from 1991 to 1997, and ran as a Libertarian in 2016.

Both are on the ballot for the primary in New Hampshire on February 11.