Top 2 Primary
Washington is the first state in the country to establish a Top 2 Primary election system, rather than a party nominating system. A Top 2 Primary narrows the number of candidates to two. The two candidates who receive the most votes in the Primary advance to the General Election, regardless of their party preference.
Each candidate for partisan office may state a political party that he or she prefers. A candidate’s party preference does not imply that the candidate is nominated or endorsed by the party, or that the party approves of or associates with that candidate.
In each race, you may vote for any candidate listed on the ballot. The two candidates who receive the most votes in the Primary advance to the General Election, regardless of their party preference. Washington voters do not declare party affiliation as part of voter registration.
Political parties do not have a guaranteed spot on the General Election ballot. The two candidates who advance to the General Election may prefer the same party, different parties, or not state a party preference. Parties are free to conduct their nominating procedures according to their own rules, at their own conventions, caucuses or meetings. This frees parties to develop their own criteria for nominations, endorsements, and other public declarations of support.
For more information see History of Washington State Primary Systems and Top 2 Litigation.