How New Hampshire's Primary Election Works

New Hampshire uses a semi-closed primary system. Registered Democrats may vote only in Democratic primaries, while registered Republicans may vote only in Republican primaries. Voters registered as undeclared may choose to participate in either party's primary.

When an undeclared voter chooses a Democratic or Republican primary ballot, they become registered with that party. After casting their ballot, they may immediately change their registration back to undeclared before leaving the polling place.

New Hampshire does not hold primary runoff elections. Candidates only need to receive a plurality of the vote to win their party's nomination, meaning the candidate with the most votes becomes the party's nominee even if they do not receive an outright majority.