William Mostoller

William Mostoller is a Republican candidate for the Idaho House of Representatives seeking District 24 Seat B, which covers Gooding County, Camas County, and portions of Twin Falls County in the Magic Valley region. He is running in the May 19, 2026 Republican primary against incumbent Rep. Steve Miller and challenger Chance Requa in a three-way race. The general election is November 3, 2026.

Background

Mostoller is approximately 40 years old, was born in Nevada on a small ranch, and was raised in northern Idaho near Priest River. He graduated Priest River High School in 2004 and attended the College of Southern Idaho for Business Management. He lives in Hagerman with his wife and six children, as described on his campaign website. He is a retired U.S. Marine Corps Corporal and combat veteran who served multiple tours including Iraq and Afghanistan as a light armored vehicle mechanic with the 3rd Light Armored Reconnaissance Battalion and was awarded a decoration for Valor. He founded and owns MVP Processing, a Hagerman-based merchant services business; has more than 20 years of experience in Idaho construction trades; and previously worked as a federal contractor and as CEO of Magic Valley Fit personal training.

Political Career

Mostoller has not held elected office; the 2026 District 24B contest is his first run for public office, per Ballotpedia. He has appeared on Citizens Alliance of Idaho's media project Idaho Signal, the Spudservative Podcast, and the Patriot Confederation podcast.

Policy Positions

Mostoller's platform calls for comprehensive tax reform to eliminate the grocery tax, gas tax, and property tax, replacing them with what he calls a "simple, uniform sales tax," per his campaign website and his KIVI candidate Q&A. On immigration he has called for statewide E-Verify, opposes amnesty, and warns of "a demographic change and a displacement of true American values and workers." In his March 2026 Idaho Signal interview he stated, "If the government shows up and tells you what you can do on your property, you honestly you grab your rifle and you kick them off your land," and warned that amnesty risks turning Idaho into a "permanent blue Democrat state" like California after the Reagan-era reforms. He pledges "no compromises or restrictions" on the Second Amendment, supports zero-based budgeting, and has signed the U.S. Term Limits pledge for congressional term limits.

Political Alignment

Mostoller is endorsed by the Citizens Alliance of Idaho PAC. He has received a 100 percent rating from the Idaho Second Amendment Alliance.

Campaign and Endorsements

Mostoller is running in the May 19, 2026 Republican primary against incumbent Rep. Steve Miller and challenger Chance Requa. Independent expenditure filings on the Idaho Sunshine portal show 2026 backing from Citizens Alliance of Idaho PAC totaling approximately $293. Idaho EdNews reports that Citizens Alliance of Idaho PAC draws substantial out-of-state money, including from a Virginia-based national affiliate ($450,000 transfer to the Idaho state PAC) and Pennsylvania gaming-related sources. Idaho Capital Sun's April 2026 fundraising coverage notes Mostoller had raised approximately $4,540 by mid-April, comparable to incumbent Miller's $4,000 and below challenger Requa's $6,350.