Party Primary Elections to select party candidates for federal, state and county offices are held in even numbered years on the third Tuesday in May. Political party rules apply to Primary Elections. You may be required to register as a member of a specific political party in order to vote in that party’s Primary Election. You may only vote in the Primary Election of one party. There are four (4) recognized political parties in Idaho: the Constitution Party, the Democratic Party, the Libertarian Party and the Republican Party.
The Idaho Democratic Party primary, excluding Presidential contests, is open to all registered voters regardless of Party. Democrats and Independents are allowed to participate in the Presidential nominating contests.
The Idaho Republican Party excludes all voters that are not registered as Republican.