How do presidential primaries work?
Primary voters choose delegates who will represent them at the party's national convention. The candidate who wins enough delegates - typically a majority - becomes the party's nominee.
A presidential primary is an election held by a state in which voters choose among candidates seeking a political party's nomination. Instead of directly selecting the nominee, primary voters are choosing delegates - people who will attend the national convention and cast votes on their behalf.
Each state is allocated a certain number of delegates based on the party's formula, which typically accounts for the state's population and its history of voting for the party's candidates. Delegates are awarded proportionally to primary results in most Democratic contests, while Republicans use a mix of proportional and winner-take-all rules.
A candidate who accumulates a majority of the total available delegates - typically winning about 15-20 states depending on the field - secures the nomination before or at the convention. If no candidate reaches the majority threshold, the convention becomes contested.
The primary process runs from roughly January through June of the election year, though official 2028 dates have not been set. States compete to hold early primaries for maximum influence, subject to party rules that penalize states that jump ahead of the approved calendar.
Related questions
Who can vote in a presidential primary?
What happens to delegates if a candidate drops out?
Related explainers
A primary is a standard secret-ballot election run by the state government. A caucus is a series of local party meetings where participants publicly declare their support and may be persuaded before delegates are allocated.
A delegate is a person authorized to represent their state at the national party convention and cast a vote toward selecting the presidential nominee. Primary voters are choosing these delegates, not the nominee directly.
A candidate must win a majority of available delegates - the exact threshold depends on the total delegates each party sets for 2028, which has not been finalized yet.