How Pennsylvania’s Primary Election System Works

Pennsylvania uses a closed primary system, meaning voters must be registered with a political party in advance in order to participate in that party’s primary election. Registered Democrats may only vote in Democratic primaries, while registered Republicans may only vote in Republican primaries.

Independent and unaffiliated voters are generally not permitted to vote in partisan primary elections in Pennsylvania. Primary elections determine each party’s nominees for offices such as U.S. Senate, U.S. House, governor, statewide offices, and state and local positions.

Pennsylvania does not use statewide primary runoff elections; instead, the candidate with the most votes in each primary wins the party’s nomination for the general election.