PHOENIX (AP) -- President Donald Trump has vowed to do away with voting by mail, but some of his Republican allies in two Western battleground states are taking a more cautious approach.

U.S. Rep. Andy Biggs, one of two candidates with Trump's endorsement in the Arizona governor's race, does not support the elimination of mail voting altogether, though he previously questioned it after Trump's 2020 defeat. His primary challenger, developer Karrin Taylor Robson, also is backed by Trump but hasn't gone as far as Biggs to declare where she stands on eliminating mail voting.

The dilemma highlights a recurring challenge some GOP candidates face heading into next year's midterm elections. They're scrambling to balance their allegiance to Trump against the desire for convenience among many Republican voters. That's especially sensitive in the Arizona governor's contest, where Trump has taken the unorthodox approach of giving his full-throated endorsement to both Biggs and Taylor Robson.

In an election cycle that historically tends to go against the sitting president's party, Trump's sweeping condemnation of mail voting gives swing-state Republicans one more reason to worry.

GOP strategist Barrett Marson said mail voting helped Republicans win Arizona races in the 2024 election, when Trump won the state overall by more than five percentage points and the party expanded its legislative majority.

"President Trump and his campaign had a very successful ballot-chasing program in 2024, and so it would be nice for him to understand sort of the way that works and how successful he was in that endeavor," Marson said.

Trump won about 51% of the 2,882,741 votes cast early in-person and by mail in Arizona. In a television interview last month, state Republican Party Chair Gina Swoboda also said the ballot chase and early vote "helped deliver this election for Republicans."

Although mail voting remains popular with voters, Trump on Truth Social last month called for an end to the practice, with exceptions for those who are very ill and "The Far Away Military." Earlier this month, he announced the relocation of U.S. Space Command from Colorado to Alabama, calling Colorado's universal mail voting system a "big factor."

Trump has long cast doubt on mail voting, claiming it's a pathway to fraud even though there is no evidence of widespread problems. He sent conflicting messages about it in 2024 as Republicans made a strategy shift to focus on early voters ahead of the presidential election.

"President Trump is committed to ensuring that every vote cast is done in a secure and transparent fashion to restore trust and integrity back to American elections," White House spokeswoman Abigail Jackson said in an email Tuesday.

In Arizona, where about 85% of voters statewide cast a mailed ballot, the issue is particularly salient. Taylor Robson and Biggs themselves both have been casting mail ballots for nearly two decades.

Arizona Republicans pioneered a vote-by-mail expansion in the 1990s. But in recent years, the state has been whipsawed by election integrity conspiracies, which have thrived in part because of vote-counting delays in Maricopa County, the state's population center. Trump, for example, lost statewide to former President Joe Biden in 2020 by 10,457 votes, or 0.3% of the nearly 3.4 million ballots cast, and falsely claimed the election was stolen. Democratic Attorney General Kris Mayes beat her GOP opponent in a 2022 election recount by only 280 votes, or 0.01 percentage points.

Maricopa County is the country's second-largest election jurisdiction, after Los Angeles County. Counting mail ballots takes more time because the envelopes must be scanned, ballots sorted and voters' signatures inspected before the ballot can be tallied.

Though Taylor Robson aligned herself with Arizona business leaders when she lost the governor's race in 2022, she has since shifted to the right. She sports a #MAGA in her X profile's bio and a "Make Arizona Strong Again" slogan. In 2022, when she did not have Trump's backing, she refused to say whether she would have certified the 2020 election results but didn't go so far as calling the election fraudulent.

Her first television ad this year centered on Trump's support of her run for governor -- after he announced that he also supports Biggs. She has said in an interview with a local radio station that she agrees with the president on all major issues that matter to Arizonans.

She side-stepped a question on voting by mail in a recent interview with KTAR, noting that she agrees with Trump on the need to "restore trust and integrity" in the elections but not explicitly stating whether or not she'd like to see mail voting repealed. Her campaign declined to elaborate.

Biggs, a former chair of the far-right House Freedom Caucus, supported Trump's false claims about the 2020 presidential election being stolen. In praising the president's budget bill, he said he would "always stand shoulder-to-shoulder" with Trump in his fight against "bloated bureaucracy."

But he breaks with the president when it comes to mail voting. Sean Noble, a Biggs campaign consultant, said Biggs doesn't support revoking mail voting. Since Trump's announcement, Biggs has encouraged in-person voting on the social platform X.

"Encouraging in person voting is not the same as repealing mail voting," Noble said in a text message. "He does not support eliminating mail voting."

Arizona's Democratic Gov. Katie Hobbs, who is running for reelection, said she would protect mail-in voting.

A similar dynamic is in play in neighboring Nevada, where incumbent Gov. Joe Lombardo, a Republican, has been strategic in his public support of Trump. He's endorsed the president but has looked to build an independent profile as a moderate in another state where close elections are commonplace.

Lombardo, who was endorsed by Trump in 2022, has stayed loyal but rejected Trump's false claims of the 2020 election being stolen.

In his reelection campaign launch Monday, Lombardo made no specific mention of mail voting.

"I promised Nevadans I would fight for common sense election reforms, like voter ID," he said.

Lombardo's 2022 election was drawn out in part because of a 2020 law requiring counties to accept mail ballots postmarked by Election Day, even if they arrive four days later.

While all states allow some form of mail voting, Nevada is among eight states and the District of Columbia that conduct all elections almost entirely by mail. In three of the last four statewide elections, more Nevadans voted by mail than voted in person. The exception was the 2024 general election, when 45% of voters cast their ballots by mail.

Lombardo, who has previously called for an end to "universal mail-in ballots" and has supported stopping mail ballot counting after Election Day, did not respond to multiple requests for comment. It's unclear whether he currently agrees with Trump's call to do away with mail voting altogether.

Associated Press journalist Maya Sweedler in Washington contributed to this report.

Trump's call to end mail-in voting creates a dilemma for GOP candidates who benefit from it