California Democrats and Republicans award delegates in each congressional district.

“So you’re gonna essentially have 53 small campaigns around the state,” says Paul Mitchell, who runs one of California’s most respected political data companies.

For example, he says, coastal Democrats don’t vote like inland Democrats. And in some districts, more people vote early by mail.

“Those kind of mechanical differences are gonna be extremely important when you’re talking about potentially somebody’s entire presidential campaign resting on being able to eke out a dozen delegates here, a dozen delegates there, going into the conventions,” Mitchell says.

And another twist: Republican delegates are winner-take-all in each district; Democrats award delegates proportionally based on how well each candidate does. Both parties also award extra delegates based on the statewide vote.