Reuters
A Los Angeles Times investigation found that roughly 73% of voters who are registered for the American Independent Party might have done so because they thought they were registering as independents.
The AIP boasts nearly half a million registered members, according to the paper, making it the state's largest third party.
The American Independent Party traces its roots back to the late 1960s, when segregationist former Alabama Gov. George Wallace ran on the party's ticket for president in 1968. The party's chairman said it's "not segregationist" anymore. Instead, he told The Times that it's a "conservative, constitutionalist party."
Democrats will allow independent voters - those who are registered as having "no party preference" - to cast ballots in the June primary. Republicans will hold a closed primary, meaning only GOP registered voters can participate. AIP registered voters can only cast ballots for candidates on the party's ballot. The deadline to change registration is May 23, per The Times.
Hollywood stars Emma Stone and Demi Moore, as well as Patrick Schwarzenegger, the son of movie star and former Republican California Gov. Arnold Schwarzenegger, were mistakenly registered with the party.
The party accounts for about 3% of the 17.2 million registered California voters.
Former Secretary of State Hillary Clinton leads Bernie Sanders, a Vermont senator, by 10 points in California, according to the RealClearPolitics average of several recent polls. More than 450 delegates are at stake for Democrats, the largest total for any of the 50 states. Sanders has traditionally fared better in states with open primaries.
Republicans, too, have their biggest treasure trove of delegates in play in the Golden State, with 172 up for grabs. GOP frontrunner Donald Trump leads Ted Cruz, a Texas senator, by 9 points, per the RealClearPolitics average.