From his corner of rural Iowa, Neil Shaffer did more than his fair share to put Donald Trump in the White House and to try to keep him there.

Shaffer oversaw the biggest swing of any county in the US from Barack Obama to Trump in 2016, and increased the then president’s share of the vote four years later. But the chair of the Howard county Republican party is not enthusiastic at the prospect of yet another Trump presidential campaign, and he blames the Democrats for driving it.

“Honestly, the Democrats are shooting themselves in the foot with these prosecutions,” he said. “Why is Trump doing so well? Because people feel like they are piling on him. If this is the Democrats’ effort to make him look bad, it hasn’t. It’s probably going to make him the [Republican] nominee and, honestly, he may win the general election again. And then whose fault would it be?”

After pleading not guilty on Thursday to federal charges over his attempts to steal the 2020 presidential election, Trump denounced the indictment as “a persecution of a political opponent”.

“If you can’t beat him, you persecute him or you prosecute him,” he said.

There are plenty who buy that line in Iowa and the rest of Trump-sympathetic America.

With Trump likely to spend a good part of the next year in one courtroom or another, after being indicted in New York, Florida and Washington on an array of charges and with more expected in Georgia before long, his supporters are more than willing to believe it is a plot to keep their man out of the White House.

One of them is Tom Schatz, a Howard county farmer on Iowa’s border with Minnesota.

“They’re bringing the charges against Trump so he can’t run against Biden. Biden is so damn crooked. We’ve never had this kind of shit in this United States, ever,” he said. “Democrats are gonna keep riding [Trump’s] ass and bringing shit up against him. They don’t quit. They just don’t like him because he’s draining the swamp, and they don’t like that.”

Schatz, like many Trump supporters, sees the prosecutions as part of a pattern of establishment attacks, from Congress twice impeaching the then president to the FBI’s investigation into alleged ties between Russia and his 2016 campaign. The same message is hammered home on rightwing talk radio stations that are often the background to the working day in rural America.

On the day of Trump’s arraignment, Buck Sexton, a former CIA analyst on AM 600 WMT in Iowa, was energetically telling his listeners, without irony, that the prosecutions undermined confidence in the electoral system.

“We are up against something we have never dealt with before,” he said. “They don’t care how reckless this is, the Democrats. It doesn’t bother them the disruption that they are doing to faith in the judicial system, faith in our elections, something that he’s talked about all the time. How can you have a fair election when one candidate has soon to be four criminal trials against him? Specifically timed to happen during the election.”

Shaffer, who works for the state as a river conservationist as well as running a family farm, has watched Trump’s support rise, fall and then bounce back.

Some support drained away to the Florida governor, Ron DeSantis, after several prominent candidates backed by the former president lost in the midterm elections last November. For a while, polls put DeSantis ahead of Trump in a primary matchup. Shaffer said his county party was split, although at the time he still thought Trump would win because his supporters had more energy and commitment.

“Now I think it’s even more so. When I speak up for DeSantis at our Republican monthly meeting, these people wearing their Trump hats don’t want to hear it. It’s such a foregone conclusion. Trump is going to get the nomination easily, whether he’s in a jail cell or in the courtroom. These people are that diehard,” he said.

Shaffer sensed the renewed vigor in Trump’s campaign when he met the former president days before the latest indictment, at the Iowa Republican party’s annual fundraising Lincoln Dinner. Trump was among 13 candidates there to argue their case before meeting party activists one on one. So was his former vice-president, Mike Pence.

“I feel bad for Pence because there were 500 people in line to see Trump and there were literally five people in the room for Pence,” said Shaffer. “Trump has that connection. Most of our group was there just to meet him.”

Shaffer said the line to see DeSantis was longer than for Pence but nothing like the one for Trump, which he took as further evidence that the rightwing Florida governor’s moment had passed and that the the prosecutions helped revive Trump’s candidacy.

“I think DeSantis is awesome. I think he’ll make a great president someday. But as long as Trump is running, there’s no way he’s gonna get the nomination,” he said.

The polls back Shaffer’s view. But among some Howard county voters, support for Trump is more ambivalent.

Tom Schatz’s son, Aaron, was a reluctant Trump voter in 2016. He voted for Obama but didn’t like Hillary Clinton. He was much more enthusiastic about Trump four years later but has cooled on him since.

For all that, Schatz believes the former president is the victim of a political conspiracy.

The dairy and corn farmer said he was more concerned about inflation, rising interest rates and falling prices for his milk than the details of the 45-page indictment laying out Trump’s attempts to overturn the 2020 election. He preferred to see the charges as evidence of a double standard in which the Washington establishment failed to properly investigate Hillary Clinton or Hunter Biden for alleged crimes.

Asked about Trump’s part in the January 6 storming of the Capitol, Schatz brushed it off as a bad thing but not very different from what he said were Democratic politicians encouraging the protests and riots that followed the killing of George Floyd three years ago.

“They burned down Minneapolis. Were they prosecuted for that?“ he asked. “Trump acted poorly when he lost, I’ll give them that. But they’re just out to get anything they can on him. Part of me thinks that all they’re going to do is unite the Trump followers. I think they’re doing more harm than good.”

Shaffer, too, is not persuaded by the detail of the indictment.

“I still don’t like a lot of what Trump was doing, a lot of what he was saying. People know he didn’t handle himself very well from election day through January 6. But does it rise to the level where he should go to jail because he said something in a phone call? I think we’re more adult than that,” he said.

Suspicions about the barrage of indictments even extends to the chair of Howard county’s Democratic party, Laura Hubka, a US navy veteran and ultrasound technologist at the city’s hospital who has no like of Trump.

“I think that they’re going after him because he’s running,” she said. “Did he break laws and is he a bad guy? Yeah. But I think if he just went into the sunset, and blathered on Truth Social, maybe they would just have left him alone. But once he ran again, people thought he’s popular enough to win again and we need to do something to stop him. They had to do something, I guess.”

The impact of Trump’s coming trials, and the evidence they lay bare, remains to be seen. But it might be expected that while diehard supporters will remain loyal through it all, those who voted for him once but then swung to Biden four years later have little reason to switch back.

Trump was defeated by 7m popular votes and 74 electoral college ballots in 2020, and some Democrats are calculating that he will struggle to overcome that deficit with the additional baggage of indictments, trials and possibly even prison time.

Yet the polls show the US’s two most recent presidents tied, including in key swing states such as Michigan.

“Every time they indict him, he goes up in the polls,” said Shaffer. “I think the Democrats are so arrogant. Some of the liberals believe that, just like they did in 2016, he’ll never be elected, he’ll never get in again. Don’t be too sure about that.”

For her part, Hubka cannot believe that the polls are that close even if the election is more than a year away.

“I feel like he could be running from prison and it’ll still be a tight race with Joe Biden. That’s what scares me,” she said.

Which raises a question about why the Democrats are not doing better in a former stronghold like Howard county.

Shaffer says Howard county is doing well in many ways, and thanks to Biden. He said the presidents’s Inflation Reduction Act has pumped money into the county, paying to renew infrastructure, including bridges and roads. Shaffer’s conservation work for the state is well funded thanks to the federal government, and that brings financial benefits to farmers. In addition, the push for green energy has resulted in a proliferation of very profitable windmills.

“We’ve got a lot of windmills around here and it’s a huge benefit. Each one of those is valued at a million dollars and we’re able to tax them and it puts money in our budget so we can build bridges and roads and have money for the schools,” said Shaffer.

“I’ve got one of my farmers has four windmills and all the roads and lines. He gets $185,000 a year from it. He built a new home. He’s got new tractors. The whole northwest part of the county used to be a more depressed area. The windmills pumped in a lot of money “

Shaffer is surprised that, with so many Republicans denouncing renewable energy, the Democratic party isn’t making more of an effort to claim credit for the benefits in Howard county.

Hubka blames the Democratic national leadership, which has been accused of overly focusing on parts of the country where a majority of the residents have a college education, unlike rural Iowa.

“They need to get some balls, be more bold. I also feel like they just are writing off the rural counties,” she said.

But Hubka is still there, campaigning and waiting to see what happens if Trump goes to prison. She bought a gun before the last election because of so many threats from Trump supporters.

“I was really very scared that I was going to get shot or hurt. It’s calmed down a bit in that sense. But who knows what happens if he gets thrown in jail,” she said.

Around the corner from her hospital, a flag hanging outside a house might be read as a warning: “Trump 2024. The rules have changed.”