Types of State Primary Elections

Closed, Partially Closed, Partially Open, Open To Unaffiliated Voters, Open or Top-Two

The laws governing state primaries are complex and nuanced to say the least, and state primary laws have been a cause of confusion among voters and election administrators alike.The manner in which party primary elections are conducted varies widely from state to state.

Closed Primaries

In general, a voter seeking to vote in a closed primary must first be a registered party member. Typically, the voter affiliates with a party on his or her voter registration application.

Partially Closed

In this system, state law permits political parties to choose whether to allow unaffiliated voters or voters not registered with the party to participate in their nominating contests before each election cycle.

Partially Open

This system permits voters to cross party lines, but they must either publicly declare their ballot choice or their ballot selection may be regarded as a form of registration with the corresponding party.

Open to Unaffiliated Voters

A number of states allow only unaffiliated voters to participate in any party primary they choose, but do not allow voters who are registered with one party to vote in another party’s primary. This system differs from a true open primary because a Democrat cannot cross over and vote in a Republican party primary, or vice versa.

Open Primaries

In general, but not always, states that do not ask voters to choose parties on the voter registration form are “open primary” states. In an open primary, voters may choose privately in which primary to vote. In other words, voters may choose which party’s ballot to vote, but this decision is private and does not register the voter with that party.

Top-Two Primaries

California and Washington use a “top two” primary format. The “top-two” format uses a common ballot, listing all candidates on the same ballot. In California, each candidate lists his or her party affiliation, whereas in Washington, each candidate is authorized to list a party “preference.” The top two vote-getters in each race, regardless of party, advance to the general election.

Presidential Primary Rules

States may have radically different systems for how they conduct their State and Presidential Primaries: Some states hold their state and presidential primaries on the same day, some hold them weeks or even months apart, and some hold the two primaries on the same day but have different rules for each primary.

See more details on each type of primary at: https://www.ncsl.org/research/elections-and-campaigns/primary-types.aspx