- Democratic congressional and state primaries: open
- Republican congressional and state primaries: open
- Democratic Presidential primary: open
- Republican Presidential primary: open
- South Carolina has nonpartisan registration. There is no option to affiliate with a political party on the voter registration form
Details of voting in congressional and state primary elections:
- Voters do not declare affiliation with a party in order to vote in party primaries, but they must choose one party's ballot.