Yes. As a result of a federal court decision in Idaho Republican Party v. Ysursa, the 2011 Idaho Legislature passed House Bill 351 implementing a closed primary system. Persons who are not members of a party may not participate in the selection of that party’s nominees. However, Idaho law does allow the political parties the option of opening their primary elections to "unaffiliated" voters and members of other political parties if they so choose. The party chairman must notify the Secretary of State 6 months prior to the primary if the party intends to open it's primary election to those outside the party.

So in primary elections, unless the party chooses to allow others outside the party to participate in its primary election, only registered voters of a political party may vote to select their party’s nominees. In other words, at primary elections, registered Republicans may vote only for Republican candidates, and registered Democrats may vote only for Democratic candidates. Persons who are registered as “unaffiliated” (meaning not affiliated with any political party) may not vote for partisan candidates in primary elections unless the party decides to allow them. Independent candidates appear on the ballot only at the general election.

Since Idaho has never required party registration prior to July 1, 2011, there are approximately 742,000 registered voters who are not affiliated with any political party. Electors can designate their party affiliation with the Democratic, Republican, Constitution or Libertarian Party or select no party affiliation (Unaffiliated) in any of the following ways:

• Fill out a new voter registration card

• Fill out a Party Affiliation Declaration form

• Declare a party at the polls at the 2012 Primary Election

• Anyone who has not declared a party affiliation by the 2012 Primary Election will be registered as an unaffiliated voter

There are elections on nonpartisan issues scheduled to be held in conjunction with primaries, such as judicial elections, bond or levy election or possibly state or local question elections. All registered voters are entitled to vote on nonpartisan issues during primaries.

Party registration requirements have no effect on general election procedures. At general elections, all voters receive exactly the same ballot and may vote for any candidate whose name appears on it, without regard to the political affiliation of the candidate or the voter.