California not only runs a modified closed presidential primary, but it also joins Washington and Nebraska in running a «top two» open primary system for all non-presidential primary elections. (gothamgazette.com)
Sometimes supporters of top - two open primary systems say that their system eliminates «spoiling», i.e., the so - called tendency of minor party candidates in a race to alter the identity of the winner. (thirdpartypolitics.us)
California has an open primary system, which means that generally speaking, voters are not restricted by party as to for whom they can vote. (politics.stackexchange.com)