Rep. Liz Cheney, R-Wyo., called former President Donald Trump a "domestic threat" Wednesday evening during a speech at the Reagan Library in Southern California

"We are confronting a domestic threat that we have never faced before – and that is a former President who is attempting to unravel the foundations of our constitutional Republic," Cheney said. "And he is aided by Republican leaders and elected officials who have made themselves willing hostages to this dangerous and irrational man."

She told the audience that Republicans "cannot both be loyal to Donald Trump and loyal to the Constitution," to a round of applause after she recounted the allegations the Jan. 6 committee, of which she is a member, has brought against Trump surrounding his actions on that day in 2021. 

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Liz Cheney speaking

Rep. Liz Cheney, R-Wyo., vice chair of the House Select Committee investigating the Jan. 6 U.S. Capitol insurrection, delivers her "Time for Choosing" speech at the Ronald Reagan Presidential Library and Museum Wednesday, June 29, 2022, in Simi Valley, Calif. The speech is part of a series focusing on the conservative movement to address critical questions facing the future of the Republican Party. (AP Photo/Mark J. Terrill) (AP Photo/Mark J. Terrill)

Cheney is one of two Republicans (Rep. Adam Kinzinger is the other) on the Jan. 6 panel and may face a steep challenge in her primary this August. The election has very little polling, but one paid for by a group supporting Trump-endorsed opponent Harriet Hageman has Cheney behind by 30 points. 

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Still, the congresswoman insisted, "No party and no people and no nation can defend and perpetuate a constitutional republic if they accept a leader who's gone to war with the rule of law, with the democratic process or with the peaceful transition of power – with the constitution itself."

Cheney also mentioned global threats like Russia and North Korea and blasted President Joe Biden for the economy, but she homed in on Trump.  

Liz Cheney speaking

Rep. Liz Cheney, R-Wyo., vice chair of the House Select Committee investigating the Jan. 6 U.S. Capitol insurrection, delivers her "Time for Choosing" speech at the Ronald Reagan Presidential Library and Museum Wednesday, June 29, 2022, in Simi Valley, Calif. The speech is part of a series focusing on the conservative movement to address critical questions facing the future of the Republican Party. (AP Photo/Mark J. Terrill) (AP Photo/Mark J. Terrill)

"The efforts Donald Trump oversaw and engaged in were even more chilling and more threatening than we could have imagined," she said, referring to testimony and other alleged revelations from the Jan. 6 hearings adding, his alleged actions are both "undeniable" and "painful" for Republicans to accept.

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Liz Cheney on Jan. 6 panel

Chairman Bennie Thompson, D-Miss., and Vice Chair Liz Cheney, R-Wyo., listen as the House select committee investigating the Jan. 6 attack on the U.S. Capitol holds a hearing at the Capitol in Washington, Tuesday, June 28, 2022. (AP Photo/J. Scott Applewhite) (AP Photo/J. Scott Applewhite)

She said she made her choice to no longer support Trump first as a mother because she wants her children and their children to live in a country where "the peaceful transfer of power is guaranteed."

Next, she made it as an American and a person of faith, she told the crowd. 

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Quoting former President Ronald Reagan, she said, "it is up to us in our time to choose and to choose wisely between the hard but necessary task of preserving peace and freedom and the temptation to ignore our duty and blindly hope for the best while the enemies of freedom grown stronger day by day."