United States presidential primary
In the United States, a presidential primary is a series of elections and caucuses within a political party. They are held to choose the party's candidate for the presidential election. This process was never included in the United States Constitution; it was created over time by the political parties. Some states hold only primary elections, some hold only caucuses, and others use a combination of both.
These primaries and caucuses are staggered generally between either late-January or early-February, and mid-June before the presidential election in November. The primary elections are run by state and local governments.