If Trump becomes the Republican nominee for president, Wyoming Rep. Liz Cheney said she would leave her political party.
"I'm going to do everything I can to make sure Donald Trump doesn't become the nominee," Cheney told Evan Smith, CEO of The Texas Tribune.
She said she wouldn't be a Republican if he is the nominee.
Cheney follows in the footsteps of her father, Dick Cheney, who served as vice president under Bush.
The vice chair of the Jan 6 committee has made it clear that she does not support the policies of the former President. Newsweek reported that Cheney voted with Trump almost all the time, but the two have publicly feuded over her refusal to endorse him.
Cheney said that he wouldn't have voted for Trump.
The congressman is a key member of the investigation into the attack on the capitol. Since she no longer has to campaign for a Republican audience that still supports Trump, Cheney may be bolder in her actions against the former president.
Representatives for Cheney didn't reply immediately.