Ballotpedia Coffee Club: How do primaries work

How do primaries work?

Primary elections are used to select the candidates that will appear on the general election ballot. Let's start with a quick overview of the types of primary elections and how they choose who can vote and how votes are counted. Generally, the rules around primaries fall under two criteria: who can participate and how is the winner determined.

Who can participate?

• Open primaries: a voter does not have to formally affiliate with a political party (as indicated on their voter registration) in order to vote in the primary or they can declare their affiliation at the polls on the day of the primary.
• Closed primaries: a voter must affiliate formally with a political party in advance in order to participate in that party's primary.
• Semi-closed primaries: previously unaffiliated voters can participate in the primary of their choosing. Voters who previously affiliated with a political party who did not change their affiliations in advance cannot vote in another party's primary.

How is the winner determined?

• Plurality voting system: the candidate who wins the largest share of the vote wins the election. The candidate need not win an outright majority to be elected.
• Majority voting system: a candidate must win more than 50% of the vote in order to win the election. In the event that no candidate wins an outright majority, a runoff election is held between the top two vote-getters.
• Top-two primaries: A top-two primary is one in which all candidates are listed on the same primary election ballot; the top two vote-getters, regardless of their partisan affiliations, advance to the general election. Consequently, it is possible that two candidates belonging to the same political party could win in a top-two primary and face off in the general election.