US progressives show strength in primaries and predict more wins ahead

In the battle for control of the Democratic party, progressives are increasingly confident they are winning. That’s how they explain the record sums of Super Pac money targeting their candidates in nominating contests for safely Democratic seats.

“There’s a set of people who are uncomfortable with a new brand of politics,” said Maurice Mitchell, national director of the progressive Working Families party. “They’re trying to set the clock back. But the genie’s outta the bottle.”

So far this election cycle, progressives have a mixed record. But a stronger-than-expected showing in last week’s...