AP® United States Government and Politics · Unit 5 · Topic 5.8
Primaries, Caucuses, and Nominations
Primaries and caucuses are how party voters pick delegates pledged to a candidate; whoever locks up a majority of delegates before the convention becomes the nominee, and the convention mostly just confirms it.
A nomination contest is really a race for delegates, people pledged to vote for a candidate at the national convention. States hold either a primary, a government-run election with a ballot, or a caucus, a local meeting where party members argue, sometimes stand in groups to show support, and then split up delegates based on who draws the most backers. The calendar is staggered: Iowa's caucus and New Hampshire's primary go first, building media coverage and a sense of momentum for whoever wins, even though together they hold a tiny sliver of all delegates. Then come more states through February and March, climaxing in Super Tuesday, when a dozen or more states vote the same day and a frontrunner usually pulls ahead for good.
Primary rules change who shows up. An open primary lets any registered voter, regardless of party, cast a ballot, which can pull in independents or even opposing-party voters looking to influence the race, often pushing results toward a more moderate nominee. A closed primary restricts voting to registered party members only, usually producing a nominee closer to the party's core base. Caucuses add another twist: because support is often declared publicly, caucus-goers face social pressure from neighbors, which can produce different winners than a secret-ballot primary would in the same state.
By the time delegates convene for the national convention each summer, the math is usually already settled. Candidates who fall behind drop out, endorse the frontrunner, and release their delegates, so one candidate typically arrives with a majority locked up. The convention still formally nominates, but it functions as a ratification and a televised unity event, not a real decision point, connecting this topic directly to how parties then pivot toward the general election and the Electoral College.
Key terms
- Delegate
- A party representative pledged to support a candidate at the national convention based on primary or caucus results.
- Open primary
- A primary election in which any registered voter may participate, regardless of party registration.
- Closed primary
- A primary election limited to voters registered with that specific party.
- Caucus
- A local party meeting where members publicly discuss and support candidates to allocate delegates, rather than casting a secret ballot.
- Super Tuesday
- The date in the primary calendar when the largest number of states hold contests on the same day.
Watch it explained
- How it worksWalk me through the nomination calendar from Iowa to Super Tuesday to the convention.
- How it worksHow does an open primary produce a different nominee than a closed primary would?
- How it worksHow does a caucus with public standing in a room differ from a secret ballot primary?
- Common mistakeWhy isn't a convention the place where a party's nominee is actually chosen anymore?
Check yourself
End of topic.