Generally, a registered voter will simply select a party's ballot at the polling place on the day of the primary.
Arguments for and against
According to FairVote, open primaries can lead to more centrist candidates being selected. As members of one party may cross over to vote in the other party's primary, they often vote for the candidate they consider least objectionable. Thus, Democrats voting in Republican primaries would vote for the most moderate Republican candidate, and vice versa, leading to both parties having more centrist nominees in the general election.
In some cases, one party's voters may try to coordinate to vote for a less-electable candidate in the opposing party's primary. If successful, "party crashing" voters could improve their own party's chances by selecting a weaker opponent for the general election.
Freedom of association
Critics of open primaries argue that they violate political parties' freedom of association.
States that use an open primary
The following states use a semi-open primary system:
- Alaska: Parties may decide who may vote in their primary election. Republicans hold a closed caucus for nominating candidates, but Democrats, Libertarians and the Alaskan Independence Party all hold open primaries.
- Georgia: Voters do not register with a party, but voters must declare an oath of intent to affiliate with the party in whose primary they participate.
- Illinois: Voters do not register with a party; however, they must publicly choose which party's ballot they will vote at the primary election.
- Indiana: Voters do not register with a party, but the ballot they get depends on their voting history, or which party they have voted for most in the past. Known as a "modified open" primary, voters must have voted for a majority of a party's candidates in the last general election in order to vote in the primary. If the voter did not vote in the last general election, the he/she is must vote for a majority of that party's candidates in the general election; however, this is difficult to enforce.
- Mississippi: Voters do not register with a party, but they must support the nominations made in that party's primary.
- North Dakota: Voters do not register with a party. Republicans hold a caucus that requires voters to have supported the Republican party in the last general election, or to do so in the next one.
- Ohio: Voters must affiliate with a party in order to vote in its primary; however, they do not choose their affiliation until they request that party's ballot in the primary.
- Texas: Voters do not have to register with a party. At the primary, they may choose which party primary ballot to vote on, but in order to vote they must sign a pledge declaring they will not vote in another party's primary or convention for that year. Voters must affiliate with the same party in runoff primaries as in the previous primary for that year.
Three states uses the top-two blanket primary process. In these states, only one primary is held with candidates from all parties participating. Thus, all voters are able to participate in the single, blanket primary. The three states are:
Other primary systems
- Ballotpedia:Index of Terms
- Closed primary
- Voting in the 2013 primary elections
- Signature requirements and deadlines for 2014 state government elections
- MTV Rock the Vote: Terms and Definitions
- How Stuff Works, "Types of Primaries," accessed April 27, 2012
- FairVote.org, "Congressional and Presidential Primaries: Open, Closed, Semi-Closed, and 'Top Two,'" accessed April 27, 2012
- The Daily Beast, "Some Suspect Foul Play in S.C. Primary," June 11, 2010
- Fair Vote, "Congressional and Presidential Primaries: Open, Closed, Semi-Closed, and 'Top Two,'" accessed May 15, 2014
- National Conference of State Legislatures Website, "State Primary Election Types," accessed January 6, 2014
- Ballotpedia research conducted December 26, 2013, through January 3, 2014, researching and analyzing various state websites and codes.
- State of Alaska Division of Elections Website, "Primary Election Information," accessed January 2, 2014
- Board of Election Commissioners for the City of Chicago, "2014 Primary: Frequently Asked Questions," accessed January 2, 2014
- Indiana Code, "Section 3-10-1-6," accessed January 3, 2014
- Ohio Secretary of State Website, "Frequently Asked Questions about General Voting and Voter Registration," accessed January 3, 2014
- Texas Statutes, "Section 172.086," accessed January 3, 2014