(NewsNation) — Three-term Republican Congresswoman Liz Cheney of Wyoming, is heading into what is being called the most significant election of her political career.

Cheney, the 55-year-old daughter of former Vice President Dick Cheney, faces challenger Harriet Hageman in the Republican primary election for Wyoming’s lone U.S. House seat.

According to a recent poll in the Casper Star-Tribune, Hageman, who has the endorsement of former President Donald Trump, holds a huge lead on Cheney.

Cheney has emerged as one of Trump’s biggest political enemies, perhaps the best known among a small group of so-called “Never Trump” Republicans. 

Cheney drew the ire of Trump and lost her position in GOP leadership after she became one of 10 Republicans to vote to impeach him over his role in the Jan. 6 attack.

Cheney is now the vice chair of the House panel investigating the Jan. 6 U.S. Capitol insurrection and has faced fallout from within her party for her role on the committee. 

Cheney’s unrelenting criticism of Trump represents the centerpiece of her unconventional campaign strategy that may well lead to her political demise.

Saying that the GOP is “very sick” and predicted it could take “several cycles” for the party to heal from internal strife and aggressive extremism, her criticism has also alienated some Republicans.

Cheney has resisted private pressure from some allies to shift away from or even soften her anti-Trump message.

Cheney’s supporters, however, understand the political paradox she faces in Wyoming, the state where Trump scored his largest margin of victory, 43 points, less than two years ago.

But Hageman is seen as more than Trump’s hand-picked candidate in Wyoming. She has barnstormed the state courting small, rural crowds in the traditional mold of Wyoming politicking. 

Hageman, a practicing attorney in Wyoming, Nebraska and Colorado, has pounded Cheney as a RINO (Republican in name only) working with House Speaker Nancy Pelosi, D-Calif., who is deeply unpopular among Republicans.

“I believe in fighting for the America first agenda, protecting our constitutional rights, reigning in government overreach, standing up for election integrity and stopping the radical Pelosi-Cheney agenda,” Hageman said in a July ad touting Trump’s endorsement.

Hageman has criticized Cheney for her absence in the state, saying, “I am going to reclaim Wyoming’s lone congressional seat from that Virginian who currently holds it.”

Suggesting Cheney is more at home in Washington, Hageman cast aside the Cheney family’s deep roots in the state.

Going to bat for his daughter, Dick Cheney appeared in a political ad, calling Trump a “coward” and a “threat to our republic.”

“In our nation’s 246-year history, there has never been an individual who is a greater threat to our Republic than Donald Trump,” Dick Cheney says in the one-minute ad.

A question looming over the primary is just how many Democrats and independents will switch parties and vote for Cheney.

On her campaign website, Cheney lists instructions for Democrats who want to change their party affiliation to vote for her in the primary. In Wyoming, a registered voter can change their party affiliation in advance or on the day they vote.

Liz Cheney is fighting for her political life, at least in the short term. She has yet to finalize any decisions about 2024, but she has not ruled out a presidential run as a Republican or an independent.

In an interview with The New York Times, she said that she is a Republican for life but not a supporter of the current state of the GOP, saying, “What the country needs are serious people who are willing to engage in debates about policy.”

The Hill and the Associated Press contributed to this report.