William Mostoller

William Mostoller: Idaho Republican Candidate for House District 24B

William Mostoller is a Republican challenger running for the Idaho House of Representatives in District 24B in the May 19, 2026 Republican primary. Mostoller, a lifelong resident of Hagerman, is a U.S. Marine Corps combat veteran, construction tradesman, and small business owner running to unseat two-term incumbent Rep. Steve Miller in a three-way primary that also includes Republican Chance Requa. District 24B covers Camas, Gooding, and a portion of Twin Falls counties in south-central Idaho.

Background

Mostoller grew up and has spent his entire life in Hagerman. He served multiple tours of duty in Iraq and Afghanistan as a member of the U.S. Marine Corps, earning decorations for valor and service, according to his campaign announcement in the Gem State Chronicle. After leaving the Marine Corps following combat injuries, he entered Idaho’s construction trades, where he has worked for more than 20 years. He owns a small business and is a family man with deep ties to the Hagerman and Gooding County area.

Political Career

Mostoller has not previously held elected office. His 2026 campaign for Idaho House District 24B is his first known run for public office. He has been active in public policy advocacy ahead of filing, including testifying before the Idaho House Business Committee in February 2026 in support of E-Verify legislation requiring employers to verify workers’ immigration status. The Idaho Capital Sun reported that Mostoller told the committee his experience in construction had allowed him to rebuild his life after his combat injuries, and that large contractors were relying on undocumented labor and pricing out tradesmen with legal work authorization. He filed for the District 24B primary on February 27, 2026.

Policy Positions

Mostoller’s campaign centers on five core priorities as outlined in his Gem State Chronicle campaign announcement: immigration enforcement, reduced government spending, Second Amendment rights, tax reform, and parental rights in education.

On immigration, Mostoller supports strict enforcement including employer accountability measures and prioritizing Idaho workers in the job market. He testified before the Idaho House Business Committee in favor of E-Verify requirements for all employers, citing his personal experience in the construction trades where he says undocumented workers have displaced legal residents, as covered by KMVT and the Idaho Capital Sun.

On taxes, Mostoller calls for eliminating the grocery, gas, property, and income taxes and replacing them with a simple uniform sales tax. On spending, he advocates for cutting what he describes as wasteful government expenditures and restoring taxpayer accountability. On the Second Amendment, his campaign calls for full expansion of gun rights with no restrictions. He has also signed the U.S. Term Limits convention pledge committing to support an Article V convention for congressional term limits.

Political Alignment

Mostoller is a Far-Right Extremist. He received a 100% rating from the Idaho Second Amendment Alliance, a no-compromise gun rights organization led by Greg Pruett that has aligned itself with far-right movements and candidates across Idaho. He appeared in an interview with Idaho Signal, the media arm of the Citizens Alliance of Idaho, a far-right activist organization that scores legislators on adherence to its ideological pledge and has backed some of the most extreme candidates in recent Idaho primaries. In a Facebook post, Mostoller criticized Gov. Brad Little as insufficiently conservative, accused state leaders of benefiting from illegal labor while opposing enforcement, and expressed ideological alignment with Sen. Glenneda Zuiderveld and Rep. Clint Hostetler, two of the most far-right members of the Idaho Legislature. Taken together, his documented ties to the Citizens Alliance of Idaho, his ISAA endorsement, and his expressed alignment with the Legislature’s far-right flank place him firmly in the Far-Right Extremist classification.

Campaign and Endorsements

Mostoller officially filed for the District 24B Republican primary on February 27, 2026, as reported by the Gem State Chronicle. He faces incumbent Rep. Steve Miller and Republican Chance Requa in the May 19 primary. No formal organizational endorsements for Mostoller had been publicly reported in independent news sources at the time of publication. The general election is November 3, 2026.

FAQ

Who is William Mostoller Idaho? William Mostoller is a Republican from Hagerman running for Idaho House District 24B in the May 2026 primary. He is a U.S. Marine Corps combat veteran, construction tradesman, and small business owner challenging two-term incumbent Rep. Steve Miller.

What district is William Mostoller running in? Mostoller is running in Idaho House District 24B, which covers Camas, Gooding, and a portion of Twin Falls counties in south-central Idaho.

Is William Mostoller an incumbent? No. Mostoller has not previously held elected office and is a first-time candidate in the May 2026 Republican primary.

What are William Mostoller’s political positions? Mostoller supports strict immigration enforcement including mandatory E-Verify, elimination of multiple state taxes in favor of a uniform sales tax, expanded Second Amendment rights, reduced government spending, and parental rights in education.

Is William Mostoller a military veteran? Yes. Mostoller served multiple tours of duty in Iraq and Afghanistan as a U.S. Marine Corps combat veteran, earning decorations for valor and service.

Profile published by IdahoVoters.com. Last updated April 2026. This profile will be updated as additional information becomes available.