Almost $4 million crowdsourced by critics of U.S. Sen. Susan Collins’ vote to confirm Supreme Court Justice Brett Kavanaugh has been transferred to her opponent, Democrat Sara Gideon.

The fundraising effort organized by Be A Hero PAC, Mainers for Accountable Leadership and the Maine People’s Alliance was launched in the months leading up to Collins’ vote in October 2018, with a promise to give the money raised to Collins’ 2020 challenger if she voted to confirm Kavanaugh.

Collins’ campaign has called the fund a bribe and released an ad this week criticizing Gideon for taking the money, which was transferred this week following Gideon’s victory in the July 15 Democratic primary.

“This has nothing to do with legitimate campaign donations to either candidate,” Collins’ campaign spokesman Kevin Kelley said in an email. “The Be a Hero fund was established solely to threaten Senator Collins. If she voted yes, they would fund her opponent but if she voted no, they would take the money away. That’s a bribe – and Senator Collins cannot be bribed.”

In response to the Collins ad, Be A Hero launched its own ad this week featuring Mainers who contributed to the fund describing how they feel about Collins’ calling their donations a bribe. A statewide mobile billboard tour also launched Friday promoting the hashtag #StopSusan.

“Senator Collins had the right to choose whether to confirm Brett Kavanaugh to the Supreme Court, and the people of Maine and across the country had a right to express their disagreement with her decision,” Maeve Coyle, Gideon’s communications director, said in a statement.

“While Senator Collins has taken nearly $6 million from corporate PAC’s and votes in their interest, Sara is proud of her strong grassroots support from more than 13,000 Mainers and 96 percent of individual contributions under $200.”

The crowdfunding campaign raised a total of $4.1 million, of which $3.8 million will go to Gideon after processing fees.

The Foundation for Accountability and Civic Trust, a right-leaning ethics watchdog group, filed a letter with the U.S. Department of Justice in September 2018 calling for an investigation into the crowdfunding campaign, saying the unusual fundraising effort constituted a bribe that tied a payment directly to Collins’ vote.

“The crowdfunding scheme was an effort to change a single Senator’s vote with the promise of campaign contributions,” Kendra Arnold, the executive director of the foundation, said in a statement Friday. “Those type of tactics undermine citizen’s trust in political officials, who should not be taking official action based upon campaign donations or personal benefit. We raised these important issues in a letter to the Justice Department, however, per the Department’s policy any action taken is confidential and not publicly available.”

Collins’ critics have pointed to hundreds of thousands of dollars in campaign donations from members of the Federalist Society, a conservative legal organization, following the Kavanaugh vote and reported on by Salon and the Daily Beast, as an indication Collins is being rewarded for her vote.

More than $41 million has been raised by the candidates in Maine’s Senate race, with Gideon leading Collins at the end of the second quarter with $24.2 million compared to Collins’ $16.9. More than $16 million has been raised by outside groups.