Primary election

Primary elections or primaries are elections held to determine which candidates will run in an upcoming general election. In a partisan primary, a political party selects a candidate. Depending on the state or party, there may be an "open primary", in which all voters are eligible to participate, or a "closed primary", in which only members of a political party can vote. Less common are nonpartisan primaries in which all candidates run regardless of party.

The origins of primary elections can be traced to the progressive movement in the United States, which aimed to take the power of candidate nomination from party leaders to the people. However, political parties control the method of nomination of candidates for office in the name of the party. Other methods of selecting candidates include caucuses, internal selection by a party body such as a convention or party congress, direct nomination by the party leader, and nomination meetings.

A similar procedure for selecting individual candidates under party-list proportional representation can be found in open list systems; in such systems, the vote for deciding which candidates on the list enter the legislature is combined with the general election (but the party itself may nonetheless hold a primary to decide which candidates are named on the list in the first place). Parties in countries using the parliamentary system may also hold leadership elections. A party's leader will typically become the head of government should that party win a majority of seats in the legislature (either in its own right or through a coalition with other parties), meaning leadership elections often select a party's de facto candidate for prime minister, much like a presidential primary.