Before the general election decides who holds an office, primaries decide who each party puts forward. Understanding them explains why some races are effectively settled months early.
Primary vs. general election
A primary narrows the field within a party — Democrats choose their Democratic nominee, Republicans choose theirs. The general election is the final contest between those nominees (plus any independents) for the seat itself.
Open, closed, and semi-closed primaries
States run primaries differently. In an open primary, any registered voter can vote in either party's contest. In a closed primary, only voters registered with a party can vote in that party's primary. Semi-closed systems let unaffiliated voters pick a party's ballot on the day.
- Open: any voter, any party's ballot
- Closed: only registered party members
- Semi-closed: unaffiliated voters may opt in
Caucuses
A few states use caucuses instead of primaries — local gatherings where party members discuss and then select delegates. They take more time and typically draw fewer participants than a primary ballot.
Why primaries matter
Turnout in primaries is usually low, so each vote carries outsized weight. In districts or states that reliably favor one party, the primary — not November — often decides who ultimately wins the office.
Frequently asked questions
Can independents vote in primaries?
It depends on the state's system. Open and semi-closed states usually allow it; closed states generally do not.
Why should I vote in a primary?
Primaries choose the actual candidates on the fall ballot. Skipping them means letting a small group pick your options.