Primary elections explained
Most Americans are familiar with the November general election. Fewer participate in the primaries that determine who appears on that November ballot. This gap between awareness and participation has enormous consequences for who actually governs.
What a primary is
A primary election is how a political party selects its candidate for the general election. Rather than party bosses choosing in a back room — which was once common — most states now ask registered voters to make the choice. Primaries were adopted progressively in the early twentieth century as a reform measure to give ordinary voters more power over the selection process. They largely succeeded, and in doing so, they fundamentally changed American politics.
Open vs. closed primaries
States vary in who can vote in a party's primary. In a closed primary, only voters registered with that party may participate. In an open primary, any registered voter may choose which party's primary to vote in on Election Day. In a semi-open primary, unaffiliated voters may participate but registered partisans may not cross over. Each system produces different incentives: closed primaries tend to favor candidates with strong partisan support; open primaries can allow more moderate candidates to win.
Why primaries matter
In many congressional districts and state legislative races, one party is so dominant that the general election is not truly competitive. In those places, the primary is the real election. Winning the dominant party's primary is tantamount to winning the seat. Voter turnout in primaries is typically far lower than in general elections — sometimes below ten percent in local races — which means that a small, motivated group of voters can have an outsized influence on who holds office. This is why primaries deserve far more civic attention than they typically receive.
Presidential primaries and caucuses
Presidential primaries and caucuses are a separate process by which voters in each state express their preference for their party's presidential nominee. Primaries work like regular elections: voters cast ballots privately. Caucuses are public gatherings where participants physically group themselves by candidate preference and discuss and revote in a more deliberative process. The results determine how a state's delegates — who will formally nominate the candidate at the national convention — are allocated.