JAMES HOHMANN: The far left is winning the Democratic civil war.

THE BIG IDEA: Tuesday was a terrible, horrible, no good, very bad day for Democratic moderates.

The success of very liberal candidates in primaries across four states is causing a new bout of heartburn among party strategists in Washington, who worry about unelectable activists thwarting their drive for the House majority. But it also reflects a broader leftward lurch among Democrats across the country since President Trump took office.

— In Nebraska, a liberal social worker and political neophyte who built her campaign around “Medicare for All” scored a shocking upset in a Democratic primary to take on Rep. Don Bacon (R). Kara Eastman, 45, beat former congressman Brad Ashford, 68, in an Omaha-area district that national Democrats believed they could pick up in November.

Eastman advocated for universal background checks to buy guns, raising taxes and decriminalizing marijuana. “I’m tired of hearing Democrats don’t have a backbone, that we don’t stand for anything,” she said in a commercial that touted her support for universal health care. “That changes now!”

Ashford had the full-throated support of the Democratic Congressional Campaign Committee, which must now reevaluate whether to invest in the race.

That’s just the initial bullet point in the wake of this week’s primary races. There’s a lot to unpack in this one — none of it good for Democrats seeking to haul their party back towards the center.