Elections in California
The Top Two Candidates Open Primary Act requires that all candidates for a voter-nominated office be listed on the same ballot. Voter-nominated offices include state legislative offices, U.S. congressional offices, and state constitutional offices. California's open primary system does not apply to candidates running for U.S. President, county central committee, or local offices.
In both the open primary and general elections, you can vote for any candidate regardless of what party preference you indicated on your voter registration form. In the primary election, the two candidates receiving the most votes—regardless of party preference—move on to the general election. Even if a candidate receives a majority of the vote (at least 50%+ 1), a general election still must be held.
Write-in candidates for voter-nominated offices can still run in the primary election. However, a write-in candidate can only move on to the general election if the candidate is one of the top two vote-getters in the primary election. Additionally, there is no independent nomination process for a general election.