You can only vote for the candidates of the party in which their records show you are registered. You are not allowed to cross over.
Independents can vote for Independents, Republicans for Republicans and Democrats for Democrats. There is no crossover and no same day registration.
If you have just reregistered, you will have to fill out a provisional ballot. Even if you have the confirmation card and your new ballot booklet for the proper party, you have to fill out the provisional ballot if their records don't show you registered for the updated party.
Provisional ballots are set aside and verified with the registration rolls at a later date. I'm not sure if they are counted same day with and are only verified later.
Hope this helps. I appreciate you asking the question. This applies to California, and others may be interested.
