Liz Cheney is a Ford-Reagan-Bush-Romney-Dick Cheney Republican. But she is not a Trump Republican.

She served as the U.S. representative from Wyoming from 2017 until January 2023.

Earlier, she had worked for Fox News for a while after she was a State Department official. She graduated from Colorado College and earned a law degree from the University of Chicago.

Cheney is a fiscal and social-issues conservative. She is an internationalist, like her father and the presidents he served.

She voted for Donald Trump twice. As a member of the House, she voted about 93% of the time for Trump-supported programs.

She is more conservative than Trump on most political issues.

But she also is a constitutionalist, someone who believes that government should be limited by a higher law, in our case, the U.S. Constitution. As a conservative constitutionalist, she believes the Constitution must still be upheld today.

This contrasts with what Trump has occasionally said about the Constitution. Shortly after he began his new campaign for the presidency, for example, he called for the “termination” of the Constitution to remove Biden and reinstall himself in the White House — immediately.

After the Jan. 6, 2021, attack on the Capitol, Cheney broke sharply with Trump. She explains why in her recently published book, “Oath and Honor.” It is a gripping, fast-paced, close-up recounting of Trump’s attempts to remain in office and the various ways congressional Republicans — especially the then-House Speaker Kevin McCarthy, Mike Johnson and Jim Jordan — supported these attempts.

Cheney is most upset by the fact that, in his attempts to remain in office, Trump repeatedly violated his oath to the Constitution. She notes that all government officials, upon assuming office, swear an oath to uphold the U.S. Constitution. They owe their loyalty to the Constitution, she says, not to any political party or individual.

The danger is real, she says. If we ignore the Constitution, we will lose our democratic form of government. “Defend the republic, daughter,” former Vice President Dick Cheney tells Liz. “I will, Dad,” she says.

Liz Cheney’s conclusions in “Oath and Honor” can be readily summarized:

• “The president of the United States (Donald Trump) summoned the (Jan. 6) mob and lit the flame of this attack. Everything that followed was his doing. None of this would have happened without the President. The President could have immediately and forcefully intervened to stop the violence. He did not. There has never been a greater betrayal by a President of the United States of his office and his oath to the Constitution.” 

• “No man who would do these things can ever be our president again.”  

• “Donald Trump had demonstrated that he is unfit for any office.” 

Cheney describes in detail how Trump’s attorneys and campaign managers repeatedly told him he had lost the 2020 election. Trump himself appeared to occasionally acknowledge this. But he also prepared in advance for ways to overturn a possible election loss. The story of how these attempts played out reads like a thriller, with the outcome uncertain up to the very end.

A valuable part of her new book recounts how Trump tried in his last weeks in office to “take over” both the Justice Department and the Department of Defense. When the attorney general quit, Trump tried to install his loyalists at DOJ. His own counsels and dozens of top Justice Department attorneys threatened to resign because of his proposed actions. He reluctantly backed down.

Trump fired his defense secretary and appointed hand-picked loyalists to run the Pentagon. This prompted Liz Cheney and her dad, himself a former defense secretary, to organize a powerful public letter signed by all 10 of the living former secretaries of defense, declaring that under no circumstances should the U.S. military become involved in elections.

That letter and a resolute Gen. Mark Milley, who was chairman of the Joint Chief of Staff, probably undermined any efforts that Trump and advisers like retired Gen. Michael Flynn may have been considering to use the military to aid in any overthrow of the government.

In January 2021, Cheney voted, with nine other House Republicans, to impeach Trump. Most of these members have since retired or been defeated. Cheney believes as many as a couple of dozen more House Republicans considered voting for Trump’s impeachment, but they feared losing their seats or “retribution” from Trump and his allies.

Cheney was vice chair of the House Select Committee to Investigate the Jan. 6, 2021, Attack on the U.S. Capitol. She was the most consequential member of that historic committee. Her book understandably uses many of the stories and facts that emerged from that committee and its final report. But her book is more readable and provides a highly personal and important insider view.

Trump told his followers in January 2021 that “we have to get rid of the Liz Cheneys of the world.” He has targeted Cheney with insults for most of the past three years. He supported her ouster from a top leadership post in her party. And he enthusiastically endorsed and campaigned for her Wyoming primary opponent in summer 2022. Trump succeeded in canceling her career as a member of Congress. It is especially sad to read about the regular Trump-inspired security threats she has had to endure.

Liz Cheney is on a mission to keep Trump from becoming president again. She says he is unfit for public office. Democrats, many Independents, and some Republicans are grateful for her work on the Jan. 6 committee. Yet, she has become a pariah in the Trump Republican Party. She understood that her vote to impeach Trump and her decision to accept Nancy Pelosi’s invitation to serve on Jan. 6 committee would likely doom her political prospects in her party.

“Oath and Honor” is a big best-seller. Trump loyalists will attack it, yet are unlikely to read it. But it might inspire some “fence-sitting” Republicans to rethink their loyalties to Trump. And it probably will inspire those who fear a second Trump term.

Meanwhile, it is hard to know what else Liz Cheney can do. She might be willing to join a third-party ticket if that is the only way to prevent a second Trump term. But she knows a third party running for president hasn’t worked out since 1860. She knows, too, that if she were to run, it might help rather than hurt Trump. And although she is a hero for many people right now, her voting record would deter many voters when it is looked at closely.

Cheney effectively debunks conspiracy theorists like Vivek Ramaswamy, who assert that the Jan. 6 insurrection was an “inside job” — some kind of plot by the FBI or our intelligence agencies. Her book is a valuable contribution to our understanding of the American experiment and the fragility of constitutionalism.

Cheney has urged young people to resolve to do what they think is right — “even when it’s hard, even when you’re afraid — especially when you’re afraid.” She has done what she thinks is right, yet it has been a bruising experience for her. Cheney has held fearlessly to the belief that those who serve this country must honor the oath they swear to uphold the U.S. Constitution.