How Primaries and Caucuses Work

Primaries are government-run elections that work like a regular election day. You go to a polling place, cast a secret ballot, and leave. They're the most common method and are used by most states for both presidential and down-ballot races.

Caucuses are party-run meetings where participants gather at a specific time and location to publicly discuss and vote for candidates. Caucuses typically require more time (often several hours) and in-person attendance, which means they tend to draw smaller, more politically engaged crowds. Only a handful of states still use caucuses.

Both methods serve the same purpose: allocating delegates who will represent the state at the party's national convention and formally nominate the candidate.

States set their own rules for who can vote in a primary. The four main types:

• Closed primary: Only voters registered with a party can vote in that party's primary. You must declare your party affiliation in advance.
• Open primary: Any registered voter can vote in any party's primary, regardless of their own registration. You choose which party's ballot to request at the polling place.
• Semi-closed: Registered party members vote in their own primary, but unaffiliated voters can choose either party's ballot.
• Semi-open: Voters don't have to publicly declare a party, but their choice may be recorded.

Your state's primary type determines whether you need to register with a party to participate. Check your state's rules well before primary day — some states have registration deadlines weeks in advance.

When you vote in a primary, you're not directly choosing the nominee — you're helping allocate delegates who will cast votes at the national convention.

• Proportional allocation: Delegates are divided among candidates based on vote share. Most Democratic primaries and many Republican ones use this method. Candidates typically need at least 15% of the vote to earn any delegates.
• Winner-take-all: The candidate with the most votes in a state gets all of that state's delegates. Some Republican primaries use this approach, especially later in the calendar.
• Hybrid: Some states use winner-take-all at the congressional district level but proportional statewide, or vice versa.

Pledged delegates are bound to vote for a specific candidate based on primary results. Superdelegates (in the Democratic Party) are party leaders who can vote independently, though recent reforms limit their role to later convention ballots.

The primary season typically begins in January or February of a presidential election year and stretches through June. The order matters — early states get outsized influence because strong performances create momentum and media attention.

• Early states: Iowa and New Hampshire have traditionally gone first, though the parties have recently reshuffled the calendar. South Carolina and Nevada also hold early contests.
• Super Tuesday: A day in early March when a large number of states vote simultaneously. It's often decisive — candidates who perform poorly on Super Tuesday frequently drop out.
• Front-loading: States have competed to move their primaries earlier, seeking more influence. The parties set rules and penalties to manage the calendar.

By the end of the primary season, if one candidate has won a majority of delegates, the nomination is effectively decided before the convention.

Each party holds a national convention in the summer before the general election. These multi-day events serve several purposes:

• Delegate roll call: Delegates formally cast their votes to nominate the presidential candidate. In modern elections, this is usually a formality since the winner is known in advance.
• Party platform: Delegates debate and adopt the party's official policy positions for the election cycle.
• Vice presidential selection: The presidential nominee announces their running mate, who is then confirmed by the delegates.
• Contested conventions: If no candidate has a majority of delegates, multiple rounds of voting occur. Pledged delegates may become free to vote for any candidate after the first ballot, and superdelegates weigh in. This is rare in the modern era but has happened historically.

• Register with a party: If your state has closed primaries, register with the party whose primary you want to vote in. Do this well before the registration deadline.
• Vote in your primary: Primary turnout is much lower than general elections, which means your vote carries more weight. Find your primary date and make a plan to vote.
• Attend a caucus: If your state holds caucuses, show up. The time commitment is real, but your influence is outsized because so few people participate.
• Become a delegate: In many states, you can run to be a delegate to your party's convention. Contact your local party committee to learn how.
• Research candidates: Don't wait until the general election to learn about candidates. Use our candidate research guide to compare their records and positions.