As Ron DeSantis sat, sweating slightly, under a bright blue sky at Iowa’s State Fair on Saturday, Trump Force One soared overhead.

The former president’s distinctive red and blue jet drew the eyes of onlookers, some turning away from Mr DeSantis to watch it descend on the fairground.

As news of Donald Trump’s arrival spread, huge crowds swarmed around the 77-year-old’s motorcade winding its way past a Ferris wheel, corn dog stands and carnival rides.  

It was an inauspicious opening for Mr DeSantis, who has staked his White House bid on halting Mr Trump’s seemingly unstoppable march to the Republican nomination here in the Hawkeye State.

The Florida governor’s appearance at the State Fair - a summer fete that is a crucial staging post for aspiring presidents - had been intended to re-launch his faltering campaign after staffing cuts and dwindling polling numbers.

As the first state to vote in the race to find the Republican presidential nominee, Iowa plays a critical role in shaping the outcome.

Mr DeSantis, 44, hopes that a win in the Midwestern state on Jan 15 will give him enough momentum to propel him to victory.

But his arrival on stage in Des Moines was overshadowed by protesters who banged cowbells and blew whistles as he made his presidential pitch.

Heather and Kara Ryan protested throughout DeSantis’ entire first stop of the day.

They shouted phrases like: ‘Go back to Florida, pudding fingers’ and ‘racist, fascist, anti-gay, Ron DeSantis, go away.’

The two also got into a few skirmishes with supporters at the rock.

— Katelyn Caralle (@Katelyn_Caralle) August 11, 2023

Speaking over the chants, beads of sweat trickling down his face, Mr DeSantis told the crowd of several hundred: “We need to win the election. The time for excuses for Republicans is over.”

He leaned into his culture warrior status, declaring the Left had awoken the “sleeping giant of mothers all across this country” by intervening in education and gender issues.

Circling overhead was a plane carrying a sign reading: “Be likeable, Ron!”

As Mr DeSantis spoke, Mr Trump was making his grand entrance to the fair - a late decision intended to upstage his rival.

The State Fair is typically an opportunity for candidates to court middle America: admiring the fair’s displays of prize livestock, eating pork chops on sticks and being grilled by voters.

True to his outsider persona, Mr Trump didn’t bother with the customary retail-politicking.

While other candidates dressed down in jeans and cowboy boots, the former president came in his trademark navy suit - though he dispensed with a tie.

“Make the farmers great again,” he declared, his security detail forming a protective ring between him and his thousands of fans.

“This is the biggest crowd they’ve ever had. I’m honoured by it,” he said. In response, the crowd chanted: “four more years, four more years”.

The latest New York Times/Siena poll in Iowa shows Mr Trump ahead with 44 per cent of the Republican vote and Mr DeSantis a distant second with 20 per cent.

Mr DeSantis’ campaign has said he will have visited the 99 counties in Iowa, a state a little larger than England, by October.

But the uphill challenge he faces to win over Mr Trump’s supporters was underscored by the reception he received roaming the fairground.

As he flipped pork chops on a grill, a gaggle surrounded him and chanted “we love Trump”.

Matthew Connell, a 27-year-old working in media marketing, stood feet away listening to the governor and wearing a white “DeSantis” T-shirt.

While he is a fan, Mr Connell is unsure the Florida governor can resurrect his campaign. “It sure doesn’t look like it right now, but we’ll see how things go,” he said.

But Tony Mercer, a 39-year-old farmer from southern Iowa, said Mr Trump’s legal battles and his marmite personality would boost Mr DeSantis.

Clutching a DeSantis sign, he said: “Too many people already know what they think [of Trump]“.

Conscious of their first-in-the-nation status, Iowans use the State Fair to sample not just deep-fried treats, but potential Oval Office occupants.

Virtually every Republican 2024 candidate is appearing at the two-week jamboree, mingling with voters among the farm animals and standing on hay bales to deliver their pitch.

Connie Adkisson has been attending the fair for more than six decades, and has met virtually every White House candidate to visit Iowa since John F Kennedy.

Ronald Reagan was her favourite. Mr Trump is perhaps a close second.

Ms Adkisson, a retiree who volunteers with children, believes the criminal indictments against him are “laughable”, and won’t stand in his way.

Nevertheless, she is willing to give every candidate appearing in Iowa a fair hearing. “I want to know what my options are,” she said.

Mr DeSantis, in her view, doesn’t have “enough experience”, but still seems to be “pretty proud of himself”.

She is impressed by Vivek Ramswamy, a 38-year-old multimillionaire biotech company founder. “Has a lot of great ideas,” she said.

Like Mr DeSantis, Mike Pence, the former US vice president, faced heckles from Trump supporters during his attendance at the fair, angered by his divergence from Mr Trump’s election rigging narrative.

Also making the rounds was Francis Suarez, the mayor of Miami. Mr Suarez said he had a unique selling point: an ability to attract Hispanic, young and urban voters -  three of the Democrats’ “core constituencies”.

He told The Telegraph he planned to beat Mr Trump by “offering voters something different”.

He said: “I think my candidacy is that. I’m someone who has a track record. I have a positive vision for the future to create prosperity for the maximum number of Americans.”

As for Ms Adkisson, no candidate has yet compared to her favourite, Mr Reagan.

She insists she is aware of Mr Trump’s faults. But she says: “I’m not voting for the pastor of my church. I’m voting for the leader of the free world. And I want a man who’s got the guts to say it as it is.”

Above all, Mr Trump is “a businessman, not a politician,” she added. “I can’t vote for another politician”.