A Democratic super PAC launched a $3.4 million ad campaign on Friday to highlight a recent report that accused Republican U.S. Sen. Susan Collins of steering millions of dollars to a defense contractor in exchange for campaign contributions.

The 30-second spot from WinSenate focuses on a recent ProPublica report about illegal campaign contributions made to a pro-Collins super PAC during her 2020 campaign.

The ad features local news reports about last week’s story. It includes an older-looking woman — a key swing demographic in the race — speaking directly to the camera.

“Susan Collins took illegal campaign money and steered millions in government contracts to the donor, but Donald Trump’s administration shut down the investigation,” the woman says. “Maybe there’s a reason Susan Collins does whatever Donald Trump wants her to.”

The big-dollar ad campaign shows how Democrats are looking to turn Collins’ central campaign argument into a liability in the closing month of Maine’s closely watched Senate race.

“Chuck Schumer is bringing his New York campaign tactics to Maine,” Collins campaign spokesperson Shawn Roderick said, referring to the Democratic leader in the Senate. “His ads keep getting fact-checked as false and now he is asking Mainers to believe someone who is doing hard time in federal prison for fraud. Mainers have never fallen for his tactics and they aren’t going to now.”

Polling leading up to ProPublica’s report had shown a tight race between Collins and Democrat Troy Jackson, a former logger and state Senate president. Jackson holds a roughly two-point lead over Collins, according to polling averages from the election website FiftyPlusOne.

The ad comes after the Senate Majority PAC, which is aligned with WinSenate, issued a Sept. 29 memo outlining its plan to make corruption a key part of its closing message to midterm voters. The group said the message ties into voters’ concerns about rising prices.

The memo notes that invoking “corrupt” and “pay-to-play politicians” is particularly effective among swing voters — a group that has repeatedly sent Collins back to Washington, D.C., despite leaning Democratic in recent statewide elections.

Republican groups are also making corruption a central argument in attacks against Jackson. They’ve run ads that highlight Jackson’s expense reimbursements while maintaining a second home in Augusta, as well as his son Chace’s work as a lobbyist while his father was Senate president.

On the campaign trail and in ads, Collins has been touting her power as chair of the Senate Appropriations Committee — the first Mainer to hold the post in 92 years. She says she’s been able to bring home $1.5 billion in federal earmarks over the last five years.

But Democrats are trying to flip the script to argue she’s using that position to benefit herself by pointing to ProPublica’s report.

Last week, the outlet reported that the FBI was preparing to open a sweeping corruption probe of Collins and other powerful politicians in 2024. But the probe was shut down after Trump returned to the White House in 2025 and disbanded the anti-corruption unit.

Collins, her campaign and her staff have all vigorously denied the allegations and called the report “outrageous” and a political hit job that’s based on the word of a convicted felon. They contend Collins was cleared of wrongdoing by the Biden administration, noting the defense contractor in question, Martin Kao, of the Hawaii-based firm Navatek, was implicating Collins to have his prison sentence reduced.

An FBI spokesperson is quoted in the story saying the bureau “ultimately found nothing implicating Senator Collins or Senator Collins’ campaign. Any suggestion otherwise is totally false.”

The WinSenate ad is part of a more than $32.7 million investment the Democratic super PAC is making in Maine, according to the media tracking firm, Ad Impact. The PAC has nearly $18.8 million in ads reserved between now and Election Day.

But Republican groups have a significant financial advantage in the race. Those groups have spent or reserved $100.5 million on ads this cycle — nearly $38 million more than Democrat-aligned groups, according to Ad Impact. Republican groups have reserved more than $37 million in ads leading up to the election.