Mark Harris

Mark Harris: Republican Nominee for Idaho Senate District 35

Sen. Mark Harris, a six-term incumbent and the Senate's Assistant Majority Leader, ran unopposed in the May 19, 2026 Republican primary for Idaho Senate District 35, receiving 6,340 votes, according to certified Idaho Secretary of State results. He faces Democrat Marty Rotz Kilhefner in the November 3, 2026 general election.

Background

Harris holds a bachelor's degree in political science from Utah State University and works as a rancher, according to his official Idaho Legislature biography. He serves on the board of Bear Lake Memorial Hospital and is a former state board member of the Idaho Farm Bureau and the Idaho Cattle Association. He and his wife, Cheryl, have four sons. Gov. Butch Otter appointed Harris to the Senate on July 23, 2015, to fill the seat vacated by Sen. John Tippets, who left to lead the Idaho Department of Environmental Quality; Otter said at the time, according to the Spokesman-Review, "Mark brings with him some valuable experiences gained while working in Idaho agriculture and serving on various voluntary boards and committees."

Legislative Record

Harris serves on the Senate Health and Welfare, Resources and Environment, and State Affairs committees, per the Legislature's 2026 roster. A politicalpotatoes.substack.com piece noted that his bill making administrative changes to the state's EMS system passed, writing: "Sen. Mark Harris's (District 35 Soda Springs) bill for EMS administrational changes passed. This will hopefully open up the door for more funding for volunteer EMS agencies around the state."

Platform

On his campaign website, Harris says: "As your Senator for District 35, I've always stood firm on my commitment to being a fiscally conservative leader who prioritizes the safety and prosperity of our community." On property rights, he says: "Idaho's Constitution guarantees the right to possess and protect property, and I am committed to ensuring that right remains intact." On regulation, he says: "I believe in small government and that means the government needs to get out of the way. The government should not be regulating small businesses out of business." Elsewhere on his site, he says: "Idaho is and should be, the best place to live and work. Keeping it that way requires lawmakers who are dedicated to conservative solutions to complex challenges, keeping government out of the way and allowing the private sector to thrive."

Endorsements

Harris's campaign website lists an endorsement from Idaho Chooses Life: "Idaho Chooses Life is proud to endorse Mark Harris for re-election to the Idaho Senate. He has been a faithful defender of preborn children and the pro-Life values which make Idaho a special place." He has also received an "A" rating and endorsement from the National Rifle Association and the Idaho Farm Bureau's Friend of Agriculture Award for scoring 100 percent on bills important to the organization.

Electoral History

After his 2015 appointment, Harris won election to the Senate in 2016 with 79.6% of the vote against Bob Fitzgerald, and again in 2018 with 76.3% against Noall Wolff, running unopposed in both general elections that followed. He ran unopposed in 2020. Following 2022 redistricting, he won a new District 35 primary with 63.7% against Doug Toomer and was unopposed in the general. He defeated Toomer again in the 2024 primary, 62.3% to 37.8%, and won the general with 77.5% against Democrat Chris Riley, according to Idaho Secretary of State canvass records. Toomer did not file for the seat in 2026.

Campaign Finance

Harris's 2026 campaign finance filings with the Idaho Secretary of State's Sunshine portal show a beginning cash balance of $56,310.32, total contributions of $49,263.03, and total expenditures of $52,926.76, leaving an ending cash balance of $56,711.02 and no debt. His largest contributor is the Bonneville County Republican Central Committee ($2,000.00), followed by Altria Client Services ($1,500.00) and $1,000 contributions from Google, Idaho Power, United Heritage Insurance, the Idaho Automobile Dealers Association, PacifiCorp/Rocky Mountain Power, St. Luke's Health Plan, J.R. Simplot, and the Idaho Cable Broadband Association.

Sources

• Idaho Secretary of State, certified results for the May 19, 2026 primary election
• Idaho Secretary of State, election canvass database
• Idaho State Legislature, 2026 member page for Mark Harris
• The Spokesman-Review, 2015 appointment coverage
• politicalpotatoes.substack.com, "A Very Special Bill"
• Mark Harris for Idaho Senate, campaign website
• Idaho Secretary of State Sunshine portal, 2026 campaign finance filings for Mark Harris