Primaries vs. Caucuses

Primaries and Caucuses

The primary and caucus systems are used to determine who the presidential nominee for each party will be.

Presidential nominees are determined during the national conventions held in July. During this convention, delegates from each state cast a vote for a presidential candidate. Whichever candidate receives the highest number of delegate votes wins the nomination for that party, becoming the presidential candidate.

Unlike in the past, delegates now are obligated to vote in accordance with the primary or caucus results of their state. There are three possible ways to determine how the delegates must vote: proportionally, winner-takes-all, or hybrid. With a proportional system, delegates must vote proportionately with the election results of that state. For example, if a candidate receives 60% of the vote in state X, then they will receive 60% of the delegates’ votes for that state at the convention. Hybrid modes effectively follow this same pattern. Winner-takes-all functions exactly as it sounds: whichever candidate receives the majority of primary or caucus votes receives all delegate votes at the convention.

So what’s the difference between a primary and a caucus?


Think of a primary as an earlier and slightly modified general election. Run and organized by the state, polling booths are set up where all eligible voters can go, cast a secret ballot, and then continue about their day. By the end of the day, the totals are tallied and published, telling the delegates how they have to vote in the convention.

There are two types of primaries: open and closed. In open primaries, all eligible voters can vote for both Republican and Democratic candidates. In closed primaries, the voter must be registered with a specific party to vote for its candidates.


Caucuses, on the other hand, are a bit more complicated. Run by the state party, there are open and closed caucuses. In closed caucuses, only registered Republicans can attend the GOP caucus and only registered Democrats can attend the DNC caucuses. In open caucuses, anyone can attend either caucus (or the caucus of a minority party), no matter their party affiliation.

The Republican and Democratic caucus systems are slightly different, but the basic format is the same. Participants gather (typically in a gym, town hall, or similar venue) and group themselves according to which candidate they support. During the course of the evening, chosen representatives have the opportunity to try to sway the minds of all other caucus-goers. At the end of the evening, whichever candidate has the most participants in their group wins.

Democratic caucuses distribute their delegate votes proportionately. In each caucus (often done by precinct or county), percentages are tallied and compared throughout the state, determining the proportionate number of delegates to represent each candidate. Each candidate in each precinct must reach at least 15 percent of the vote to be eligible.

Most Republican caucuses, however, are winner-take-all, meaning that the candidate that has the largest group will receive all delegates from that precinct.