Despite the rising number and growing influence of California’s Decline to State voters, the major political parties can still shut out them out of the primaries if they choose.
Operating on what is known as a modified closed party system, the state's six official political parties - American Independent Party, Democratic Party, Green Party, Libertarian Party, Peace and Freedom Party, and the Republican Party - determine 135 days prior to the date of the primary for each election cycle whether or not Decline to State voters can participate in their primary.