George Conway, former conservative lawyer and ardent critic of President Donald Trump, has filed paperwork to run for Congress in New York City as a Democrat. The move aims to replace retiring Representative Jerry Nadler in the crowded Democratic primary for New York’s 12th Congressional District.

Conway, who is the ex-husband of President Trump’s former Senior Counselor Kellyanne Conway, announced his candidacy through official Federal Election Commission filings Monday. While he has not publicly launched a campaign or made explicit comments about the bid, the paperwork indicates his intent to contest the primary race in one of the nation’s most Democratic districts.

A source close to Conway described his decision as follows: “George is a seasoned fighter against Trump and Trumpism, and he’s considering taking that fight to Congress. Today, he filed paperwork that is a prerequisite to run. He will have more to say in the new year after the holidays.”

Conway previously stated on Substack that he has “put my money where my mouth is” and said, “I’m going into the arena,” though he did not explicitly confirm the bid at the time.

The 12th Congressional District primary features a field of candidates including former Merrill Lynch managing director Alan Pardee, Jack Schlossberg (grandson of President John F. Kennedy), state Assembly members Micah Lasher and Alex Bores, gun safety activist Cameron Kasky, and journalist Jami Floyd, a former White House fellow in the Clinton administration.

Conway’s announcement follows his recent decision to leave “The Bulwark” podcast, where he had described his move as “either the stupidest thing I’ve ever done or the best thing.”