You will have to re-register to vote. Either online or in person.
You could register online at SDVote.com, fill out a registration form found at your local library, post office or DMV and mail it in or register at the Registrar of Voters office in person.
Party affiliation is one if the things that you must fully re-register for. You can also call the ROV and they will mail you an affidavit. If you want to register to vote in the primary the deadline is Feb 18th for california.
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