Iowa's influential evangelical voters were once decidedly lukewarm on Donald Trump. But if recent polls are accurate, born-again Christians will carry him to victory on Monday in the Republican caucuses. What has changed?

The video is bombastic, even by Mr Trump's standards. Just consider the title: God Made Trump.

"God looked down on his planned paradise and said, 'I need a caretaker,'" a voiceover intones over a minimalist piano track. "So God gave us Trump."

The former president, according to the narrator, is carrying out the will of God. He's "a shepherd to mankind" who will "fight the Marxists" with "arms strong enough to wrestle the deep state".

The video is based on So God Made a Farmer, a 1978 speech by American radio host Paul Harvey which extols the virtues of simple rural American life.

Independently produced by a group calling itself "Trump's Online War Machine", the clip started to pick up steam a week ago when Mr Trump shared it with millions of followers on his Truth Social account. It immediately enraged some religious leaders here in Iowa.

"He's not the saviour," said Michael Demastus, pastor of the Fort Des Moines Church of Christ in the state capital. "Our allegiance as evangelicals is to Jesus, not to the Republican Party or to Donald Trump."

But despite Mr Demastus' insistence that many voters agree with him - and that a surprise is in store on Monday - opinion polls show a different story, with Mr Trump poised for a runaway victory over his Republican rivals.

Evangelical support is crucial here in Iowa, with born-again Christians expected to make up around two-thirds of all Republican caucusgoers.

They are a diverse voting bloc - made up of various denominations and including more traditional churchgoers along with others who may not even regularly go to a church, yet still define themselves as evangelical.

In 2016, Mr Trump picked up just 22% of this group on the way to a second-place finish behind Texas Senator Ted Cruz, who like previous Iowa Republican winners made faith a major part of his campaign.

But since that time, when many were still sceptical of the blunt-talking New York businessman trailed by sex scandals, Mr Trump has made born-again Christians a key part of his voter base. In this Iowa caucus, surveys suggest he will get the support of roughly half of evangelical voters.

Steve Scheffler, a Trump supporter and president of the influential Iowa Faith and Freedom Coalition, said that Mr Trump had delivered for the religious right, and they expected him to do so again at a moment that many see as the most important election in their lifetimes.

"Evangelical voters know that we live in a society where things have gone awry," he said, mentioning culture war issues over gender identify and "wokeness".

"They believe things are very bad, and if they don't get involved, they are going to get much worse."

Mr Trump's opponents, particularly Florida Governor Ron Desantis, have put a lot of effort into earning the support of religious voters. Mr DeSantis won the coveted endorsement of Bob Vander Plaats, head of The Family Leader, a conservative Christian non-profit group.

But Mr Scheffler argued that big-name endorsements weren't very important - "they're nice to have, but they don't move the needle".

And Mr Trump has hit back, collecting endorsements of his own and sending surrogates such as his former housing secretary Ben Carson on a tour of Iowa churches.

Mr Carson alluded to Mr Trump's unpredictability as he made the case for his former boss at a stop here last week.

"Would you rather have someone whose tongue is maybe a little wild, but has incredibly good policies that make your life better?" he asked the congregation. "Or someone who has a silver tongue and says all the right things and has terrible policies which ruin your life and those of your children and grandchildren?"

Self-described conservative evangelical David Pautsch is a huge fan of Mr Trump, and the former president is part of the reason he's decided to run for Congress in Iowa's 1st district, challenging a Republican incumbent from the right.

Mr Pautsch lives here in Davenport, a city of around 100,000 people in eastern Iowa, and was collecting signatures to back his campaign from hundreds of locals who braved frigid weather to visit a gun show at an exhibition centre.

Easily shifting between quoting Bible verses and Mr Trump's campaign messages - including immigration and his insistence that he did not lose the 2020 election - Mr Pautsch called the people who criticised the God Made Trump video "too uptight and literal".

Christians, he said, need to boldly demand that conservative religious values be injected into the heart of American government. "Our country was never meant to be run without God."

Kedron Bardwell, a political science professor at Simpson College in Indianola, just outside Des Moines, said that Mr Trump had a key advantage over his rivals - a track record that aligned with evangelical priorities.

His appointment of three conservative justices to the Supreme Court - and the overturning of Roe v Wade, which for decades had held that there is a constitutional right to abortion - is a key part of that record, as is his decision to move the US embassy in Israel from Tel Aviv to Jerusalem.
Politics and religion fuse

If the polls turn out to be accurate, another crucial factor might be an evolving sense of what it means to be evangelical - one that is increasingly aligned with Mr Trump's particular flavour of right-wing politics.

Although church attendance is in long-term decline across the country, according to the Pew Research Center the number of white Americans describing themselves as "evangelical" went up during Mr Trump's presidency. And the group most likely to start using that label to describe themselves were the president's supporters.

"In some ways 'evangelical' has become a political label more than a theological description," said Mr Bardwell, who studies religion and politics and is himself a long-time member of the evangelical community.

He described a deepening divide - mirrored in wider society - between church elites and the masses.

And he said that the decline in church attendance over time had meant that many of those who considered themselves religious were less influenced by spiritual leaders and more by right-wing media and politicians - Mr Trump foremost among them.

The former president regularly refers to religious themes and rarely misses a chance to contend that he is being persecuted by the authorities. Mr Bardwell said that he particularly appealed to "spirit-led" evangelicals, who see the divine playing out on the American political stage.

"There's a portion of the evangelical community that's very attracted to the idea that God knows everything and God appoints leaders," he said. "They believe that Donald Trump is the appointed leader at this moment in time."

On Sunday, most churches in this city in eastern Iowa were closed due to the winter storm that has sent temperatures plunging.

But whether Iowa's believers will ignore the cold and turn out in force for Mr Trump on Monday will be a decisive factor in the Republican race.