When two Orange County Republican congressmen — Ed Royce and Darrell Issa, both of whom were facing tough races this November— declared earlier this month that they wouldn’t seek re-election, Democrats were elated. Without an incumbent on the ballot, they believed, one of the many Democrat challengers who’d already declared their candidacies would surely emerge victorious in each district.

Well, maybe. There’s a wild card in this electoral deck that renders those outcomes uncertain, and it’s not just President Trump’s popularity or the state of the economy. It’s the structure of California elections: more precisely, our crazy “jungle” primary.