Candidates for U.S. President who seek their party 's nomination participate in primary elections run by state governments, or caucuses run by the political parties. Unlike an election where the only participation is casting a ballot, a caucus is a gathering or "meeting of party members designed to select candidates and propose policies. '' Both primaries and caucuses are used in the Presidential nomination process, beginning in January or February and culminating in the late - summer political party conventions. Candidates may earn convention delegates from each state primary or caucus. Sitting presidents generally do not face serious competition from their party.
who votes to make someone a presidential party nominee
delegates