About 50 people gathered around the room. Several had no intention of voting for the candidate. Several more were journalists from as far afield as Britain and the Czech Republic. Sandwiches and cookies were laid out on a side table.

Joe Walsh has modest ambitions for the Republican caucuses in Iowa on Monday. Challenging an incumbent president from the same party is usually a thankless task. When that incumbent is Donald Trump, it is doomed not only to failure but indifference.

While Democrats are locked in a titanic struggle, captivating the media, the forgotten Iowa caucuses of 2020 pitch Trump against Walsh, a former congressman from Illinois, and Bill Weld, a former governor of Massachusetts. Both seem token efforts, tennis balls bouncing off a tank.

“There are a lot of people who don’t know a Republican caucus is happening,” said Charles Siler, communications director for Walsh, after the campaign stop at a community organisation called Urban Dreams in Des Moines on Friday night. “We expect the turnout to be low but there’s a real chance for us because of that: we have the advantage of low expectations.”

An outright victory, he admitted, would be “the most insane thing ever”.

Siler accused the Republican National Committee (RNC) and state parties of stitching up the nomination before the race has begun, denying access to voter data, threatening to blacklist donors and, in some states, keeping Walsh off the ballot altogether.

“It’s basically a campaign on the outside,” he said.

Trump’s absolute monarch status in the party was emphasised by senators’ vote on Friday to block witnesses and documents at his impeachment trial, assuring him of a speedy acquittal. There is zero appetite for a challenger. If the party’s objective is make sure Walsh and Weld don’t get talked about, it appears to be succeeding.

Walsh tweeted on Saturday that Jeff Kaufmann, the Republican chairman in Iowa, “is a Trump tool. Like so many of these GOP state party chairs, he kisses Donald Trump’s ring on a daily basis. And like his master, Jeff Kaufmann will lie all the time.”

The previous night at Urban Dreams, wearing blue jacket, blue shirt and blue jeans, Walsh admitted it has been a steep learning curve.

“I knew when I did this it was a long shot,” he told the Guardian. “I said at the beginning, I thought it was really, really important that a Republican do this. I’ve been discouraged because I did not see all the mean un-American things the party would do.

“My party is a cult. I’m a conservative Republican; Fox News won’t have me on. Conservative media will ignore me because they’re a cult with Trump. The Republican parties in each state: they are a cult for Trump. I didn’t sufficiently get all of that and that’s made this really hard.”

But the 58-year-old added: “Every time I’m out there talking primarily to Republican voters, because that’s what I’m trying to do, there are a lot of Republicans that get angry at me and we get threats every day and it can get ugly… but I’m always amazed at the number of Republicans who tell me, ‘I like some of the things Trump’s done, Joe, but I’m exhausted with Trump.’ Every day it’s the Donald Trump show. So I think I have an opportunity to do better than people think and I hope I can do that in Iowa.”

Voters questioned Walsh about topics including student loans, the national debt, diplomacy and his pernicious lie, since recanted, that Barack Obama is Muslim.

“I think we’re all a little bit racist, period,” the candidate replied, adding that the catalyst for his apology was the 2016 election. “I think Trump is the worst of all of us. Having him in the White House was like a cold slap for me … I asked, ‘Oh my God, on my worst day, did I sound like Trump?’”

Such past flaws make it even less likely that Walsh, who belonged to the Tea Party and is now a Chicago-area radio talk-show host, will dent Trump’s monopoly. John Olsen, a voting rights activist, said afterwards: “I think he’s a political shock jock. That’s what this was more than anything else. But I do respect how he came here and had conversations with us. He was willing to listen.”

Olsen, 50, agreed that the uncompetitive Republican caucuses have hardly registered in the public consciousness.

“They might as well change it to the ‘Trump party’ instead of the ‘Republican party’. He totally dominates. The No 1 reason he mustn’t be re-elected is he’s a bully.”

Andrea Black, 61, a retired physician, welcomed Walsh’s efforts. “I’m a Democrat but I am so supportive of a Republican who is willing to step out of the gridlock and point out Trump is a demagogue.”

Weld, 74, who ran for vice-president in 2016 as a Libertarian, is also campaigning in Iowa. In a Guardian interview in October, he said: “My sense more broadly, being on the hustings, is everyone’s exhausted by Trump … They’d rather think about healthcare and other issues that have more to do with their daily lives.”

Walsh and Weld are expected to fight on in the New Hampshire primary on 11 February, but South Carolina and Nevada cancelled their contests in a show of allegiance to Trump. And both men’s financial resources are dwarfed by the president’s war chest.

The Trump campaign is dispatching more than 80 surrogates to Iowa to gather recruits and donations, keep its operation match fit and steal at least some of the Democrats’ thunder.

Chris Ager, one of New Hampshire’s three representatives on the RNC, told the Associated Press: “Even though it’s a foregone conclusion that the president will win the Republican primary, we still want them to go out and vote. We don’t want to cede the ground to the Democrats just because they have more enthusiasm.”