Primary and Caucus: What is the difference?

What to Know

The words primary and caucus are often used in a very similar way, especially when the topic is politics. However, one notable difference between them is that caucus is often used to refer to a group of people who meet to choose candidates, and primary tends to refer to an election that is held to choose candidates.


Caucus and primary are political words that we often see used in very similar settings, and with nearly identical meanings. However, there are some ways in which you might want to distinguish between them: caucus frequently refers to a meeting of members of a political group to choose a candidate (or candidates) for an election, and primary usually refers to an election in which members of the same political party run against each other for the chance to be in a larger and more important election.

We define caucus as “a closed meeting of a group of persons belonging to the same political party or faction usually to select candidates or to decide on policy.” Here are some examples of how it might be used:

This year’s leader was chosen in a caucus of party members.

Every year at these caucuses members chose candidates for these legislative positions.

Caucus can also mean “a group of people united to promote an agreed-upon cause.”

The Congressional Black Caucus met earlier this month.

This year a number of student caucuses are attending the meeting in the hopes of getting funding.

Primary, when used in a political sense, can be used to mean caucus (in the sense of “a meeting of people selecting candidates”), but often has the meaning “an election in which qualified voters nominate or express a preference for a particular candidate or group of candidates for political office, choose party officials, or select delegates for a party convention.” Here are some examples of primary used in this manner:

The primaries in this year’s presidential election are particularly exciting.

The Governor was unopposed in her own party, so there was no primary election that year.

So far we have only discussed these two words when they are used as nouns; both may also function as verbs, and in this part of speech their meanings are slightly more distant from each other. Caucus means “to meet in or hold a caucus” (as in “The committee caucused to select the most promising candidates”). Primary, however, means “to run against an elected official in a primary election” (as in “He supported the program so that he would be less likely to be primaried in the next election”).