Nate Silver of FiveThirtyEight reports that Democratic and Republican Party elites had a good night in America. In most of the primary elections held on Tuesday, establishment-backed candidates prevailed.

• Democrats qualified in all of California’s 53 congressional districts. Given the state’s “jungle primary” system, where the top two finishers advance to the general election regardless of party, there was a risk too many candidates could split the left-wing vote.
• Democratic senator Dianne Feinstein easily outdistanced her primary challenger, Kevin de León.
• The gubernatorial election will pit the incumbent lieutenant governor, Democrat Gavin Newsom, against party-backed Republican John H. Cox.
• In New Jersey, incumbent Democratic senator Bob Menendez was renominated, despite being caught up in a corruption scandal.
• Establishment-backed Matt Rosendale, the state auditor, won the Republican Senate nomination in Montana.
• The moderate Dusty Johnson won the Republican nomination for South Dakota’s sole House seat.

It wasn’t a spotless night for the “party decides” theory, which holds that party leaders use their influence to guide voters to the best candidates. In California’s 50th congressional district, for example, the party’s favorite, Josh Butner, placed behind the Republican incumbent, Duncan Hunter, and another Democrat, Ammar Campa-Najjar.

But the balance is clearly in favor of “the” parties, which goes some way to rehabilitating a theory that argued against a victory for Donald Trump in 2016.