On Saturday, the leadership of California’s Democratic Party endorsed state Sen. Kevin de León in his campaign to oust Sen. Dianne Feinstein. It was an upset—not least because Feinstein has been in office since 1992. She won 44 percent of the vote in California’s primary election in June; de León trailed in second place with 12 percent—not a great showing, but enough to qualify for the November ballot under the state’s top-two primary system.