PROVO, Utah (AP) — Republican voters in Utah will decide on Tuesday whether the state’s most famous moderate conservative, retiring U.S. Sen. Mitt Romney, will be succeeded by someone similarly willing to challenge GOP hard-liners or a farther-right candidate who pledges to fall in line with former President Donald Trump.

The primary duel between GOP factions will test whether Trump’s influence and appeal have grown among Republican voters in Utah, a rare Republican stronghold that half-heartedly embraced the former president in past elections.

A suburban mayor, Trent Staggs, who rode Trump’s endorsement to a GOP convention nomination for Romney’s seat, is hoping it will also propel him past U.S. Rep. John Curtis, the more moderate front-runner in Tuesday’s primary.

Curtis has pitched himself as the alternative to Staggs, the mayor Riverton, and two other contenders who have spent much of the race arguing over whose policy positions most closely align with Trump’s.

Curtis, the former mayor of Provo who started out as a county-level Democratic Party official, is the only Republican in the race who has not outright endorsed Trump’s reelection bid. He has been compared to Romney for pushing back against more extreme members of his party, particularly on climate change.

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Another candidate for the seat, former state House Speaker Brad Wilson, has the financial advantage after loaning his campaign $3 million. He was considered a strong contender before a loss to Staggs at the April convention relegated him to a long shot in the primary. Jason Walton, who has pitched himself as a businessman in the style of Trump, is also running.

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Curtis could get a further boost if supporters of the former president split between Staggs, Wilson and Walton.

The Republican primary winner is highly favored to win in November over Democratic nominee Caroline Gleich in a state that has not elected a Democrat to the Senate since 1970.

Gov. Spencer Cox is also set to face his primary challenger, state Rep. Phil Lyman, on Tuesday.

Cox, a moderate Republican who took office in 2021, is expected to win even after he was booed earlier this year by GOP convention delegates, who tend to lean farther right. Lyman is a former county commissioner turned state legislator who espoused false claims of election fraud following the 2020 presidential election.

Lyman is best known for organizing an illegal ATV ride in 2014 to protest federal officials closing a southeast Utah canyon to motorized vehicles to protect Native American cliff dwellings, artifacts and burial sites. A judge in 2015 sentenced him to 10 days in jail and three years of probation after a jury found him guilty of misdemeanor illegal use of ATVs and conspiracy. Trump later pardoned him in December 2020.

The winner of the Republican primary for governor is heavily favored to win in November over Democratic nominee Brian King, a state representative.

Also Tuesday, five Republicans are battling for the open 3rd District U.S. House seat that Curtis is vacating to run for Senate.

In Utah’s 2nd District, Trump-backed U.S. Rep. Celeste Maloy is seeking her first full term on Capitol Hill after winning a special election last fall. She faces challenger Colby Jenkins, a retired U.S. Army officer and telecommunications specialist, who is endorsed by Romney’s counterpart, U.S. Sen. Mike Lee.

Primaries will be held Tuesday for other state and national offices, including the 1st District U.S. House seat, attorney general, state auditor, state Senate, state House and state Board of Education.