Richard Painter, former President George W. Bush’s White House ethics lawyer who was also an executive at a left-wing “watchdog group,” announced on Monday that he will be running for former Minnesota Senator Al Franken’s Senate seat as a Democrat.

While announcing his candidacy on Monday, Painter, who has been one of the most vocal advocates of impeaching or removing President Donald Trump from office, said he is officially “out of the Republican Party” and said Trump is a “threat to our constitution,” according to the Minneapolis Star Tribune.

Painter has been one of CNN’s and MSNBC’s most prominent useful idiots, as both networks have routinely introduced him as “former President George W. Bush’s top ethics lawyer” and refused to tell their viewers that Painter was the Vice Chairman of the the left-wing and anti-Trump CREW (Citizens for Responsibility and Ethics in Washington) organization.

When Media Matters’ David Brock was elected as CREW’s Chairman of the Board in 2014, Politico observed that it was a move intended “turn the group into a more muscular” attack dog. Brock left the left-wing’s group’s board after Trump’s election, but Politico noted that CREW was still part of “the constellation of political groups in” Brock’s network intent on raising $40 million to combat Trump.

Painter also reportedly vowed on Monday to “stand firm against what President Trump is threatening to do to our country.”

“Republicans insist that if you’re going to run for political office, you have to be loyal to President Trump,” Painter reportedly added. “This is wrong. This is not the America I want to live in. This is not the America I want my children to live in.”

Later on MSNBC, Painter, who has never given Trump the benefit of the doubt on issues like “Russia Collusion,” refused to say he believed the numerous women who have accused Franken of sexual misconduct and assault, repeatedly saying that it was up to the Senate Ethics Committee to decide. Instead, he said the top priority should be getting rid of Republicans on Congress who do not oppose Trump.

On cable television and Twitter, Painter, along with Rep. Maxine Waters (D-CA), has been an enthusiastic proponent of impeachment or the “25th Amendment solution.”

But a Quinnipiac poll released last week found that though 71% of Democrats want the House to begin impeachment proceedings if Democrats regain control after November, just 38% of Americans want Trump impeached. The poll found that a majority of Americans (55%) oppose impeachment proceedings against Trump.

Painter will challenge Sen. Tina Smith (D-MN)—whom Governor Mark Dayton appointed to Franken’s Senate seat after the comedian resigned in December after multiple women accused him of sexual harassment—in an August DFL primary. The special election to serve the remaining two years of Franken’s term will be held in November.