Joe Wiederien was an unlikely candidate to challenge a Republican congressman in one of the nation’s most competitive districts.

A fervent supporter of former President Trump, Wiederien was registered as a Republican until months earlier. A debilitating stroke had left him unable to drive. For a time, he couldn’t vote because of a felony conviction.

But he arrived last month at the Iowa Capitol with well over the 1,726 petition signatures needed to qualify for the ballot as a conservative alternative to first-term Republican Rep. Zach Nunn.

Similar stories have unfolded across the country.

For the past year, a group called the Run Patriots Project has recruited Trump supporters to run as independent candidates in swing districts where they could siphon votes from Republicans. In addition to two races in Iowa, the group recruited candidates in Nebraska, Montana, Virginia and Minnesota. All six recruits described themselves as retired, disabled — or both.

The group’s operation provides few clues about its management, financing or motivation. But interviews, text messages, emails, business filings and other documents reviewed by the Associated Press show that a significant sum has been spent — and some of it traces back to Democrats.

Dirty tricks are as old as American elections, but the efforts this year could have profound consequences in the fight to control Congress, which is expected to be decided by a handful of races.

“I was thinking, well, it would be nice to be in Congress and get to work with President Trump,” Wiederien, 54, reflected in an interview outside the Veterans Affairs hospital in Des Moines, where he was seeking treatment for a leaking incision on his head from previous brain surgery. “It looks like it’s a dirty trick now.”

Wiederien withdrew his candidacy last month after he says it became clear he’d been manipulated into running. As with other recruits, his story begins with Facebook, where the Patriots Run Project operated a series of pro-Trump pages and ran ads that used apocalyptic rhetoric to attack establishment politicians in both parties while urging conservatives to run in November.

Once recruited, they communicated with a handful of operatives through text messages, emails and phone calls. In-person contact was limited. Run Patriots Project advised them about what forms to fill out and how to file required paperwork.

In at least three races, petition signatures to qualify for the ballot were circulated by a Nevada company that works closely with the Democratic consulting firm Sole Strategies, according to documents, including text messages and a draft contract, as well as the firm’s co-founder. In Iowa, a different Democratic firm conducted a poll testing attacks on Nunn, while presenting Wiederien as the true conservative.

Nunn on Monday called the effort a plot “to steal this election.”

“I am outraged to see anyone prey on hardworking Iowans or deceive voters,” he said.

Despite the ties to Democratic firms, there is a scant paper trail to determine who is overseeing the effort.

Patriots Run Project is not a registered business in the U.S., nor is it listed as a nonprofit with the IRS. And it has not filed paperwork to form a political committee with the Federal Election Commission. The only concrete identifying detail listed on the group’s website is a P.O. box inside a UPS store in Washington, D.C.

Messages left at email addresses and phone numbers for the group’s operatives went unanswered.

Jason Torchinsky, a prominent Republican election lawyer and former Justice Department official, said investigators should take interest. “There could be a wide variety of federal and state criminal violations,” he said.

In Iowa, it is a crime to deprive or defraud voters of “a fair and impartially conducted election process,” while in Virginia ”conspiracy against rights of citizens” is a felony.

Thomas Bowman, who is 71 and disabled after a kidney transplant, said he believes he likely was recruited to run against Democratic Rep. Angie Craig of Minnesota to split the conservative vote and help Craig win reelection in the suburban Minneapolis district. But the self-described constitutional conservative expressed gratitude for free help getting signatures.

“They got me on the ballot,” Bowman said. “If I had to do that all by myself, I couldn’t do it.”

In Montana, Dennis Hayes was recruited to run as a Libertarian against GOP Rep. Ryan Zinke. The group found a donor to give him $1,740 to cover his candidate filing fee, Hayes recalled.

Robert Reid, a widowed retiree running against Republican Rep. Jen Kiggans in southeastern Virginia, said he was contacted by Patriots Run Project after posting his views to Facebook. His sole in-person contact was when a man drove to his home in a Mercedes SUV to drop off his completed petition signature paperwork.

In Nebraska, Army veteran and Trump supporter Gary Bera said he was asked to run as an independent against Republican Rep. Don Bacon. The district, which includes Omaha, is the state’s most competitive. Plans changed abruptly last month when he was informed that the group had not collected enough signatures for him to qualify.

In Iowa, the group recruited longtime GOP activist Stephanie Jones to run as an independent against Republican Rep. Mariannette Miller-Meeks. Jones said the group paid to gather signatures for her but fell short.

Wiederien wants Patriots Run Project to be investigated.

The group convinced Wiederien to change his party affiliation from Republican to unaffiliated so he could qualify. They assured him a 2013 felony conviction wasn’t disqualifying and arranged for a firm to gather signatures across the district.

Those signatures were gathered by Common Sense America, a Nevada limited liability company created in February. A company disclosure filing in Colorado, which requires signature gatherers to register, lists a phone number for a co-founder of the Democratic consulting firm, Sole Strategies.

“We work very closely with Common Sense America,” said Zee Cohen-Sanchez, the co-founder.

Last month, a poll attacked Nunn, calling him “an errand boy for the uniparty elite,” while painting Wiederien as the pro-Trump conservative in the race.

A spokeswoman for the firm that operated the poll, Dynata, said that its customer was Patinkin Research, which says it “has worked to elect dozens of Democratic candidates.”

When it was time to submit his petitions, Wiederien was driven by a Patriots Run Project operative to Des Moines, where they met a man in an office near the Capitol. He gave them paperwork and a binder full of his signatures. All Wiederien had to do was sign a form.

Not long after he heard from Republicans who convinced him he’d been tricked into thinking the Patriots Run Project had Trump’s support and he withdrew his name from the ballot.

Foley and Slodysko write for the Associated Press. Slodysko reported from Washington.