(WASHINGTON) — Wyoming Rep. Liz Cheney has gone from House GOP leadership to party gadfly in the span of just over 18 months as she stands out as the loudest Republican critic of former President Donald Trump — which could cost her her job in Tuesday’s primary

After first winning election in 2016, Cheney quickly rose through the ranks to become the No. 3 House Republican, with rumored aspirations toward the speakership. She was also one of Trump’s most reliable votes in Congress, backing him on nearly every issue, according to FiveThirtyEight.

Yet her continued, impassioned rebukes of Trump and his allies over last year’s insurrection brought an even swifter political downfall — one that saw her booted from her leadership perch and her state party, an increasingly isolated apostate in a party still led by Trump.

“She could have cruised to another term if she had just kept her head in the sand like everybody else did,” Mark Christensen, a former Campbell County commissioner and Cheney ally, told ABC News. “But she’s not really the person who does that. She’s not really that person who shies away from a fight.”

Cheney began her House career boasting a legendary last name in Republican politics and sterling conservative credentials.

After an earlier false start as a candidate — seeking a Wyoming Senate seat in the 2014 cycle — she won Wyoming’s only House seat in 2016, the same year Trump won the White House.

While she did note during her campaign that she and Trump differed on foreign policy, she focused much of her bid on domestic issues, lambasting former President Barack Obama and even hinting that she was open to joining the hardline House Freedom Caucus, which today is filled with some of her most vocal detractors.

“Wyoming needs a strong voice in Congress to lead the effort to undo the devastating policies of the last seven and a half years and restore our freedom. I will be that voice,” Cheney said after winning her primary that year. “I will be that leader.”

Two years later, after winning only her second House term, she was elected by Republican members to be their conference chair, making her the third-highest ranking GOP lawmaker in the chamber.

While campaigning for the leadership spot, she pushed for the implementation of an aggressive messaging platform for the party.

“We need to be able to drive our message across all platforms,” she said at the time. “We need to own the daily news cycles. We need to lead and win the messaging wars. Too often we have found ourselves playing catch up without access to useful information, and we have not been on offense. Constantly playing defense in the battle of communications is a recipe for failure. We need to work as a team to use all our messaging tools to drive our agenda.”

Her rapid rise fueled whispers she had her eye on the speakership one day. That chatter only grew when she decided to stay in the House in 2020 rather than run for an open Senate seat, which many considered to be hers for the taking.

During her first two terms in Congress, Cheney built a staunchly conservative record, voting with Trump nearly 93% of the time, according to FiveThirtyEight’s analysis. And while disagreements with the then-president flared over foreign policy, Cheney did not stand out as a major roadblock to his messaging or domestic agenda.

On top of that, her allies in Wyoming recall having someone in the House who would keep a strong eye on local issues.

“With Liz, we actually would have in-depth policy discussions and then we would discuss together what our approach was going to be for, say, approaching Interior on a policy or something with Department of Energy or something else. And then not only that, she would actually do the follow up herself and then we hear back from her again, too. And I never got that from any other elected official,” said Christensen, the former county commissioner.

Yet last year’s Capitol attack marked an inflection point for Cheney, who made underscoring Trump’s role with the mob a focal point of her work — transforming her political fortunes nearly overnight.

She quickly and repeatedly denounced Trump and, when she was still the conference chair, became the highest-ranking Republican to vote for his impeachment. She later agreed to serve as the vice chair of the select House committee investigating the riot and the former president’s unfounded election fraud claims, lending it a sheen of bipartisanship.

While Cheney has traveled to Wyoming for smaller campaign events, the highly publicized work of the Jan. 6 panel swamped her travels — landing her in hot water both in Washington, where House Republicans were angered at her focus on Trump (who insists he did nothing wrong), and in Wyoming, a state he won with 70% of the vote in 2020.

“After she jumped in on the Jan. 6 thing, and she jumped in on the impeachment … she was nowhere to be found. She wasn’t meeting with the people. She doesn’t care about us,” local voter Myrna Burgess told ABC News.

Cheney’s political peril was put into stark relief when Trump endorsed Harriet Hageman in September and made ousting Cheney a top priority as part of his ongoing campaign of retribution against GOP lawmakers who turned against him.

“Unlike RINO [Republican in name only] Liz Cheney, Harriet is all in for America First. Harriet has my Complete and Total Endorsement in replacing the Democrats number one provider of sound bites, Liz Cheney. Make America Great Again!” Trump said in a statement at the time.

Cheney allies insist she’s still the right person for the job, casting her reelection bid as a broader fight for the direction of the GOP.

“This is bigger than one person’s presidency. This is our Constitution. This is our history. This is what we’re going to be remembered for. And that’s exactly what Liz is remembering,” Republican state Rep. Landon Brown told ABC News. “And there’s a lot of people in my district alone, but as well as other people out there, that they feel the exact same way.”

Cheney has focused her campaign messaging around that theme, shedding the Republican red meat that characterizes other House campaigns and adopting a more forward-looking lens.

“Here’s my pledge to you: I will work every day to ensure that our exceptional nation long endures. My children and your children must grow up in an America where we have honorable and peaceful transitions of power. Not violent confrontations, intimidation and thuggery. Where we are governed by laws and not by men. Where we are led by people who love this country more than themselves,” Cheney said in her closing ad.

Yet in a sign of her increasingly rough chances in a state where voters can change their registration the day of the primary, her campaign has been advertising how non-Republicans can back her.

Jim King, a political science professor at the University of Wyoming, put it bluntly: “There aren’t enough Democrats.”

As FiveThirtyEight has noted, public polling in the race has been sparse but favors Hageman. Speculation has already begun over where Cheney’s future ambitions lie beyond the House, including among her supporters, some of whom maintain that the possibility of defeat is really just a hidden victory.

“This race is the first battle in a much larger and longer war that Liz is going to win, because the future of the country depends on it,” said one ally. “And, regardless of what the results in this election turn out to be, she is going to lead a broad coalition going forward of Americans across the political spectrum who will stand up for freedom and restore the foundational principles that Donald Trump continues to dangerously undermine.”

Cheney has been rumored as a potential 2024 presidential candidate who could run as an anti-Trump Republican. And while she insists she’s focused on her reelection, she hasn’t ruled out a future White House run.

“I don’t know if she’d want to stay in politics. She could probably go to Virginia and may get back in, but I don’t know if she would get the Republicans support if she came back. I don’t know what she’d do,” said Natrona County Commissioner Paul Bertoglio. “I feel almost gut-punched because I really like her. And I am sorry that she’s most likely going to lose. And that’s self-inflicted.”

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