What defines a closed primary?

A closed primary is defined as a system in which only declared members of a political party are allowed to vote in that party's primary elections. This structure is designed to ensure that the candidates selected for the general election genuinely represent the values and interests of the party’s registered members.

By restricting participation to only those who have declared their affiliation with the party, closed primaries aim to prevent members of opposing parties from influencing the selection of a party's candidate. This can help maintain the integrity and cohesiveness of the party's platform and policy positions as they move forward into the general election.