California Code, Elections Code - ELEC § 7660

A committee may remove any member who during his or her term of membership affiliates with, or registers as a member of another party.

A committee may remove any member, other than an ex officio member, who publicly advocates that the voters should not vote for the nominee of this party for any office, or who gives support or avows a preference for a candidate of another party who is opposed to a candidate nominated by this party.