Updated December 4, 2023 at 10:23 AM ET

Republican Liz Cheney has made no secret of her criticism of former President Donald Trump. It's what made her an outcast in her own party and cost her her job in Congress last year.

The former Wyoming representative was one of just 10 Republicans to back his second impeachment in 2021. She became one of two Republicans on the House committee investigating the Jan. 6 attack on the U.S. Capitol, for which she explicitly blamed Trump.

Cheney's vocal and sustained criticism of the former president led to her losing her leadership role as the No. 3 House Republican and, eventually, her primary campaign for reelection.

Now, with Trump leading the polls in the 2024 Republican primary, Cheney is ramping up her efforts to keep him out of the Oval Office. She tells NPR's Morning Edition she hasn't ruled out her own presidential run in 2024 for that reason.

"I look at it very much through the lens of stopping Donald Trump," she said. "And so whatever it will take to do that is very much my focus. I think the danger is that great that that needs to be everybody's top priority."

This week Cheney releases Oath and Honor: A Memoir and a Warning, a no-holds-barred accounting from inside the Republican party of the days before and after Jan. 6, Trump's efforts to remain in office after losing the 2020 election and her often-lonely role in trying to thwart them.

Cheney name-checks members of GOP leadership too, including former and current House speakers Kevin McCarthy and Mike Johnson.

Cheney tells Morning Edition's Leila Fadel that the dangers she describes in the book are ongoing, from Trump's defiance of the institutions meant to check him, to the Republican politicians who she says put their own career ambitions ahead of their duty to the Constitution.

"People really, I think, need to understand and recognize the specifics, the details of what he tried to do in terms of overturning the election and seizing power and the details and the specifics of the elected officials who helped him," she said. "I do think it's very important for people to understand how close we came to a far greater constitutional crisis — and how quickly and easily — in a way that is, frankly, terrifying."

Cheney does credit a handful of brave Republicans in state and federal offices from stopping "the worst of what could have happened." But she says many of those people won't be there the next time around. The stakes for the country, she adds, "couldn't be higher."

"All of these things that we know Donald Trump and those who enabled him did before, they will do again," she said. "And people who are willing to abide by that, including Republicans in Congress, can't be trusted with power. And that's something that voters need to have at the forefront of their minds when they go into the voting booth in 2024."

Cheney lays into Republican leaders for their embrace of Trump

Cheney isn't afraid to name names in her book.

Among them: She describes McCarthy, the former speaker, as a coward and hypocrite who knew Trump's election claims to be false but defended them publicly anyway. She calls Johnson, the current speaker, an election denier who was easily swayed by Trump's flattery well before he ascended to House leadership.

She invoked such examples, she says, to show how "it didn't take much for people to decide that they were going to ignore the most fundamental obligation I believe elected officials have."

She says many Republicans — herself included — anticipated Trump would bring legal challenges immediately after the 2020 election and then concede by the time the Electoral College met to certify its results.

Courts across the country dismissed more than 50 lawsuits from Trump's team alleging electoral fraud. Trump and his allies focused on overturning the election results through an elaborate scheme that culminated in the Capitol riot, as detailed by the Jan. 6 committee's investigation and alleged by a federal grand jury in Washington, D.C., where he faces criminal charges.

Cheney says in the days after Jan. 6 there was "near unanimity in the sense that Donald Trump was responsible for what happened."

Republicans proposed legislation that would have censured Trump, and floated a bipartisan commission to investigate what it called a "domestic terrorist attack."

"It was common sense," she added. "We'd lived through it."

But that near-unanimity began to dissipate very quickly, which she attributes to two factors: elected officials putting their own political ambitions ahead of their oath to the Constitution, and their fear — including of violence.

Cheney writes that some members of Congress told her at the time that they believed Trump should be impeached but couldn't vote that way because they were afraid for their security and that of their family. She urged listeners not to gloss over that fact.

"People really need to stop and think about: What does it mean in America that members of Congress are not voting the way that they believe they should because they fear violence instigated by, then, the sitting president of the United States?" she adds, calling that "a place we haven't been before."

And she says once her colleagues took that position they were able to rationalize it, which helps explain where the party stands now.

"Once you've accepted something that is so indefensible, then it's hard ever to sort of go back and say, 'Well no actually, I should have stood against that.'"

Why the Jan. 6 panel's work matters — and continues

Cheney backed Trump's agenda some 93% of the time during her Congressional career. But says that after Jan. 6, as she saw it, "there never seemed to be a choice."

"It was very clear what was right and what was wrong," she added. "It was very clear that we had gotten to a point where the president had crossed lines that could never be crossed. And as Republicans, we had a particular obligation to say, 'No, we won't support this.'"

In July 2021, then-House Speaker Nancy Pelosi announced her picks to serve on the Jan. 6 panel: seven Democrats and Cheney, who, at the time, was still in GOP leadership. After a back-and-forth with McCarthy that led to him rescinding his Republican picks, Pelosi also appointed Adam Kinzinger, a Republican Trump critic who did not seek reelection in 2022.

Cheney says it would have been inconceivable to her a year earlier that she would be accepting a committee appointment from Pelosi, with whom she disagreed vehemently on policy matters. She doesn't recall the two ever speaking more than a few sentences to each other in Cheney's six years in Congress.

But she says she didn't hesitate to accept, and their relationship became "absolutely indispensable" as Pelosi worked to support the committee's efforts.

"As passionately as we both care about our views on a whole range of issues, and they're different, we both knew immediately that that did not matter as much as doing everything we could to defend the Constitution," Cheney said.

All members of the Jan. 6 committee recognized that "partisanship could not rule the day," and that they needed to let the witnesses and the evidence speak for themselves, which is what Cheney believes made it successful.

The committee held ten televised hearings that attracted millions of viewers, culminating in an 800-page report and four criminal referrals of Trump to the U.S. Justice Department.

And while some of the people singled out by the committee as collaborators are facing racketeering charges in Georgia, many others remain in positions of political leadership — and Trump leads the Republican primary pack, despite facing 91 felony counts across four criminal cases.

Cheney says the committee's work was "crucial and indispensable" both in terms of informing the Justice Department's work and presenting evidence of Trump's involvement for the historical record. And she says it's far from over.

"Looking to the future requires that we acknowledge what happened and how dangerous it was and certainly not put those same people back into office again," she added. "Making sure that that story is written and that story's told is very important as we think about, particularly, the election that's coming up next year."

Cheney says stop Trump first, then reform conservative politics

Cheney was a notable figure in conservative politics well before she was elected to represent Wyoming in Congress in 2017. She worked on her father Dick Cheney's campaign when he was George W. Bush's running mate in 2000, and focused on promoting democracy in the Middle East as a State Department aide in Bush's administration.

She says she grew up in Republican politics and believes in the values of the party that former President Ronald Reagan, for example, embodied. But she doesn't recognize them in today's GOP, which she says has become "an anti-constitutional party."

She points to the moment at the first Republican primary debate, when six out of the eight candidates onstage raised their hand to show they would support Trump as the nominee even if he were convicted.

"I think if the party goes down the path of nominating Donald Trump, certainly the party itself will have lost any claim to be a party that is, in fact, supportive of the Constitution," Cheney added.

She says it's a misconception that a second Trump term "wouldn't be that bad" because of the separation of powers and institutions that some have suggested would restrain him.

One of the main messages of her book is that people can't actually count of them to work: a House led by Johnson full of lawmakers who have pledged allegiance to Trump, courts whose rulings Trump has made clear he will ignore, a Senate confirmation process that Trump could avoid, radical far-right figures who he would appoint to his administration.

"Our republic can't sustain that," Cheney said, adding that "the Republican Party, as it exists today, is dangerous to the country."

She says Republican leaders have chosen Trump and can't be counted on to stop him. But she called on the majority of Americans who do not support Trump (63% of Americans viewed him unfavorably as of a July Pew Research Center poll) to mobilize against him at the polls.

"I think the most important thing to do now, without question, is to make sure we stop Donald Trump," Cheney said. "What American politics looks like after that, what the Republican Party — or a new Republican Party or a new conservative party — looks like after that remains to be seen."

The broadcast interview was edited by Reena Advani and produced by Lilly Quiroz.

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