William Mostoller

William Mostoller: Idaho Republican Candidate for House District 24B

William Mostoller is a Republican candidate running for the Idaho House of Representatives in District 24B in the May 19, 2026 Republican primary. He is challenging two-term incumbent Rep. Steve Miller in a three-way primary that also includes Republican Chance Requa. District 24B covers Gooding, Camas, and a portion of Twin Falls counties in south-central Idaho.

Background

Mostoller is a U.S. Marine Corps combat veteran, small business owner, and longtime Hagerman resident. According to his campaign website, Mostoller served multiple tours of duty in Iraq and Afghanistan with the Marine Corps and earned decorations for valor and service. He has cited his military service as a formative influence on his views regarding government authority, accountability, and public policy.

Mostoller is a 20-plus year veteran of Idaho’s construction trades and is the founder of MVP Processing, a merchant services business based in Hagerman that serves small businesses across the state. His campaign filing announcement, published in the Gem State Chronicle in March 2026, describes him as a lifelong Hagerman resident and “true conservative” running to represent working families, farmers, and small business owners across the district.

Mostoller has also publicly committed to supporting congressional term limits through a U.S. Term Limits pledge, aligning with national efforts to limit service in federal office.

Political Career

Mostoller is a first-time candidate for the Idaho Legislature and has not previously held elected office. His 2026 campaign for Idaho House District 24B is his first known run for public office, with no prior legislative voting record, committee assignments, or election history.

Policy Positions

Mostoller has organized his campaign around five pillars: immigration reform, reducing government spending, Second Amendment rights, tax reform, and property rights.

On immigration, Mostoller has called for statewide E-Verify requirements and for holding accountable those who harbor or traffic illegal immigrants, framing the issue around protecting Idaho workers and ensuring a fair job market. On fiscal policy, he has expressed support for cutting government spending and reducing the overall tax burden on Idaho families.

On taxes, Mostoller has proposed eliminating Idaho’s grocery, gas, property, and income taxes and replacing them with a uniform sales tax. On the Second Amendment, he has pledged to defend gun rights without compromises or restrictions. On property rights, he has framed government overreach on private land as a bedrock issue and committed to defending Idahoans’ right to own, use, and control their property.

Detailed positions on areas such as education, healthcare, and land use have not been extensively documented in independent reporting and are primarily outlined through campaign materials.

Political Alignment

Mostoller is aligned with the Conservative Activist wing of Idaho Republican politics. His self-identification as a “true conservative,” his emphasis on aggressive immigration enforcement and structural tax restructuring, and his campaign rhetoric framing Idaho’s current leadership as insufficiently conservative all place him within the activist-conservative movement.

Mostoller has publicly criticized Idaho Governor Brad Little in campaign communications as insufficiently conservative, asserting in a Facebook post that the governor was opposing certain Magic Valley candidates and arguing that some state leaders benefit from illegal labor while failing to prioritize enforcement of immigration laws. He has also expressed ideological alignment with Sen. Glenneda Zuiderveld and Rep. Clint Hostetler, both of whom are associated with the Magic Valley Liberty Alliance-aligned wing of the Idaho Republican Party.

Mostoller has received a 100% rating from Greg Pruett’s Idaho Second Amendment Alliance and was interviewed by Idaho Signal, the media project of the Citizens Alliance of Idaho, in March 2026.

Campaign and Endorsements

Mostoller filed for the District 24B Republican primary on February 27, 2026, the final day of the filing period. His campaign is based out of Hagerman and centers on themes of fiscal restraint, border security, and government accountability. The general election is November 3, 2026.

FAQ

Who is William Mostoller Idaho? William Mostoller is a Republican candidate for Idaho House District 24B, a U.S. Marine Corps combat veteran, and a Hagerman-based small business owner running in the May 2026 primary.

Is William Mostoller a military veteran? Yes. Mostoller served in the U.S. Marine Corps and is a combat veteran of Iraq and Afghanistan with decorations for valor.

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

Is William Mostoller an incumbent? No. Mostoller is a first-time candidate and has not previously held elected office.

What are William Mostoller’s political positions? Mostoller’s campaign is organized around five pillars: immigration reform with E-Verify enforcement, reducing government spending, Second Amendment rights, replacing grocery/gas/property/income taxes with a uniform sales tax, and property rights.

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