County · Ada ·See your exact ballot on VoteIdaho
Two-way race: turnout matters
Erik Olson D
Erik Olson is the only non-Republican on the ballot, so this is a two-way race and turnout is what matters. Be realistic: Arnold won this office by about 17 points in 2022.
Method rule 3 · How we pick
The Assessor sets the taxable value of property in Ada County, runs property tax relief programs such as the homeowner's exemption and the property tax reduction program, and handles vehicle registrations and titles (DMV). The Assessor does not set tax rates; those are set by the county, cities, schools and other taxing districts. (source)
Republican · incumbent
Ada County Assessor since January 2023; attorney and former CPA who served on the Ada County Highway District commission from 2005 to 2021.
“We can deliver fair and equitable assessments and provide excellent service to our community. Both. That’s the standard.”
Pull quote on her re-election campaign website (the page is undated; the date is when it was read). · 2026-09-26 · Re-Elect Rebecca Arnold (campaign website)
Democrat
Running on modernizing the Assessor's Office, adding digital services and helping homeowners get every property tax exemption they qualify for.
“My first promise to every voter is to provide a different type of campaign, free from mudslinging and muckraking, and focused on the changes I intend to bring to this office! I don't believe the current incumbent is a bad person, I simply believe I can do better for Ada County.”
Introduction on the home page of his campaign website (the page is undated; the date is when it was read). · 2026-09-26 · Erik for Idaho (campaign website)
| 2022 Ada County Assessor | Arnold (R) 58.7, Berg (D) 41.3 | R+17.4 | source |