On March 22, California State Senator Ben Allen introduced SCA 21. It says that write-in candidates for a partisan office in the primary cannot advance to the general election, even if they place second, unless they receive at least 65 write-ins (if running for statewide office) or 40 write-ins (if running for U.S. House or legislature).
Currently, anyone who comes in second for a partisan office in the primary advances to November, even if the write-in total is only one vote. If the legislature approves this idea, it would then go on the ballot for a vote of the voters, because it is a constitutional amendment, and it amends the part of the State Constitution that set up the top-two system. Thanks to Dave Kadlecek for this news.