Former U.S. Rep. Liz Cheney, the once high-ranking Republican from Wyoming who torpedoed her political career by breaking forcefully with former President Donald Trump, said Wednesday she would be voting for Democratic Vice President Kamala Harris in November.

During an event at Duke University, Cheney told students that it was not enough for her to simply oppose the former president, if she intended to do whatever was necessary to prevent Trump from winning the White House again, as she has said she would.

“I don’t believe we have the luxury of writing in candidates’ names, particularly in swing states,” Cheney said, speaking to students in the hotly contested state of North Carolina. “As a conservative, as someone who believes in and cares about the Constitution, I have thought deeply about this and 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.”

The room erupted in cheers after she made her unexpected announcement.

The decision by Cheney, whose endorsement Harris’ campaign had been courting, to shift from condemning Trump to backing the Democratic presidential nominee was striking even from one of the most vocally anti-Trump Republicans in the country.

Harris’ top aides had said they were not certain whether Cheney, who shares few policy positions with the vice president, would go a step further and make an outright endorsement of Harris, or simply spend the time between now and Election Day laying out the case against Trump. A daughter of former Vice President Dick Cheney, she is pro-gun and anti-abortion and favors a stronger national defense.

Cheney’s speech was an important show of support for Harris, whose campaign has hired a full-time national Republican engagement director and featured Republicans onstage at the nominating convention last month.

Declined convention speaking slot

But Cheney had remained silent until now. She chose not to speak at the Democratic National Convention, making the decision to wait for a stand-alone moment closer to when early voting was set to begin.

It was her latest break with the Republican Party after losing her leadership position and then her seat for condemning Trump after the Jan. 6, 2021, attack on the Capitol and voting to impeach him. She spent her final months in Congress serving on the committee that investigated the Capitol assault, and has continued to speak out against Trump.

In a series of upcoming appearances in key states, Cheney plans to make plain the practical implications of a second Trump term, talking with specificity about his abuse of the intelligence community and his attempt to corrupt the Justice Department.