A conservative lawyer with a passion for thwarting environmentalists, Harriet Hageman would appear to be an ideal candidate to carry Donald Trump’s rightwing banner into November’s midterm elections.

On Tuesday night she beat the incumbent and member of Wyoming’s political royalty, Liz Cheney, for the thinly populated western state’s solitary seat in the US House of Representatives.

After trouncing Cheney, Trump’s most vocal critic within the Republican party, Hageman, 59, has a clear run at election success. In an overwhelmingly red state, Cheney defeated her Democratic challenger in 2020 by a margin of almost three votes to one.

Hageman, however, has not always been such an enthusiastic passenger aboard the Trump train.

Her stance has shifted from calling him “the weakest candidate” in the 2016 primaries, when she attempted to help maneuver the Texas senator Ted Cruz into the Republican presidential nomination, to “the greatest president of my lifetime” when she eagerly embraced Trump’s endorsement as his chosen candidate to topple Cheney, his latest bete noire.

Neither is this her first foray into politics. She was a losing candidate in Wyoming’s 2018 contest for state governor, finishing a distant third to the eventual winner, Mark Gordon, and one other in the Republican primary, with barely 20% of the vote.

Hageman’s political positions are rooted in the minutiae of her career as a trial lawyer representing Wyoming’s ranchers, and advocating for energy industries against federal protections for water, land and the endangered gray wolf.

A 1989 graduate of the University of Wyoming’s college of law, her most successful case, according to the New York Times, was persuading a judge in 2003 to block regulations from Bill Clinton’s presidency protecting millions of acres of national forests from road-building, mining and other development.

She is a vocal supporter of the fossil fuel industry, telling supporters at a campaign event earlier this month that coal was an “affordable, clean, acceptable resource that we all should be using”.

She has previously also angered activist groups including Defenders of the Wild for her positions on endangered species.

In 2017, as an attorney for the ultra-conservative Mountain States Legal Foundation, she praised a US appeals court for cutting through “emotional arguments” and upholding the delisting of gray wolves.

The following year, the Sierra Club accused Wyoming of “waging a war” on wolves through hunting and allowing a “scorched earth” policy that threatened the species’ recovery from near-oblivion.

Hageman was late in her campaign in converting to Trump’s false assertion that his 2020 election defeat by Joe Biden was fraudulent.

In her victory speech on Tuesday night, she said: “Wyoming has spoken on behalf of everyone who is concerned that the game is becoming more and more rigged against them.”