Republican former Rep. Liz Cheney on Wednesday said she would support Kamala Harris for president, ending weeks of speculation about how fully she would embrace the Democratic ticket.

Cheney, who co-chaired the House investigation into the Jan. 6, 2021, attack, became a fierce Donald Trump critic and was ousted in her 2022 Republican primary in Wyoming as a result. She made her announcement at an event at Duke University. In a video posted on the social media network X, she finished by talking about the “danger” she believed Trump still poses to the country.

“I don’t believe that we have the luxury of writing in candidates’ names, particularly in swing states,” she said. “As a conservative, as someone who believes in and cares about the Constitution, I have thought deeply about this. Because of the danger that Donald Trump poses, not only am I not voting for Donald Trump, but I will be voting for Kamala Harris.”

Harris’ campaign chair, Jen O’Malley Dillon, said in a statement Wednesday night: “The Vice President is proud to have earned Congresswoman Cheney’s vote. She is a patriot who loves this country and puts our democracy and our Constitution first.”

The daughter of former Vice President Dick Cheney, Liz Cheney has been perhaps Trump’s highest-profile Republican critic. She joins other Republicans, including fellow Jan. 6 committee member and former Rep. Adam Kinzinger of Illinois and former Rep. Denver Riggleman of Virginia, as backers of Harris. More than 200 alumni of the Bush administrations and the Republican presidential campaigns of the late Sen. John McCain and Sen. Mitt Romney announced their endorsement of Harris last week.

Cheney was in House Republican leadership at the time of the Jan. 6 attack, but broke with most of her caucus over Trump’s responsibility. She lost her leadership post and was one of the few Republicans willing to serve on the Jan. 6 committee, which was appointed by Democrats who controlled the House at the time.