How Montana’s Primary Election System Works

Montana uses a partially open primary system, meaning voters do not register with a political party when they register to vote. At the polling place, voters choose which party’s ballot they wish to vote in and may only participate in one party’s primary election during that election cycle.

Because Montana does not maintain party registration, voters are free to choose a Democratic, Republican, or other available party ballot each primary election. Montana’s primaries are used to select each party’s nominees for offices such as U.S. Senate, U.S. House, governor, statewide offices, and state and local positions.

Montana does not use statewide primary runoff elections; instead, the candidate with the most votes in each primary wins the party’s nomination for the general election.