A key congressional race in California will test progressives' appeal

Randy Villegas, a populist insurgent, has won the Democratic primary for a House seat representing California’s Central Valley

At first glance, a recent Democratic primary in California’s Central Valley was just another skirmish between the party’s progressive wing and its more moderate establishment.

This time, the contest was won by populist insurgent Randy Villegas. But what sets the outcome apart from similar primary battles is the stakes.

This wasn't a fight over a safe Democratic seat. Villegas will be the standard bearer against Republican Rep. David Valadao, one of the most promising targets for Democrats desperate to retake the U.S. House majority and slow down President Donald Trump.

The November race will test the theory, popular on the left, that voters will flock to progressive, anti-establishment candidates even in places that have traditionally favored Republicans.

“A populist message isn’t just for blue districts or certain parts of the country," said Ravi Mangla, a spokesperson for the Working Families Party, one of the progressive groups that backed Villegas. “It can win anywhere people feel like politics is not working for them.”

"More than ever, voters across the political spectrum want candidates who are willing to stand up to power,” Mangla said.

The National Republican Congressional Committee dismissed Villegas' chances, even though the state's Democratic leaders recently redrew the district to make it easier to flip this year.

“Democrats know Villegas can’t beat Congressman David Valadao, as he embraces the same failed policies that have made California more expensive, less safe, and harder for working families in the Central Valley," said spokesperson Christian Martinez.

The Villegas victory comes during an election season in which substantial parts of the Democratic base are rejecting the candidates that party bosses see as their best shot at winning power in Congress.

Graham Platner overwhelmingly won the Democratic Senate primary in Maine this week after Senate Minority Leader Chuck Schumer's preferred nominee, Gov. Janet Mills, dropped out with lackluster support weeks before the election.

A combat veteran and oyster farmer, Platner has never held elected office before, and he's endured controversies over past relationships with women, inflammatory online posts and a since-covered tattoo recognized as a Nazi symbol.

In Michigan, Rep. Haley Stevens is entangled in a three-way contest for the Democratic Senate nomination against state Sen. Mallory McMorrow and progressive favorite Abdul El-Sayed. The primary is Aug.