How Colorado's Primary Election Works

Colorado uses a semi-open primary election system. Registered Democrats and Republicans receive their party's primary ballot, while unaffiliated voters automatically receive both Democratic and Republican ballots but may vote and return only one. The candidates who receive the most votes in each party's primary advance to the November general election.

Unlike some states, Colorado does not hold primary runoff elections. A simple plurality of the vote is enough to secure a party's nomination, meaning the candidate with the most votes wins even without an outright majority.