The stalemate by now is well known: Nine moderate or conservative Democrats have rebelled against their party’s leaders and say they will block consideration of the budget blueprint necessary to allow the social policy measure championed by the party’s left flank to pass this fall with only Democratic backing unless the House immediately votes on the Senate-passed bipartisan infrastructure bill. A broader coalition of 19 Blue Dog Democrats also want the infrastructure vote to come as soon as possible…

The left-right divide, however, oversimplifies the swirling undercurrents that are roiling the Democratic Party.

Some of the same Democrats confronting their leaders on the budget resolution have allied with them to fight off challenges from the insurgent Democratic left in the coming primary season. Representative Josh Gottheimer of New Jersey, a leader of the recalcitrant nine, founded the Team Blue political action committee with Representatives Hakeem Jeffries of New York, the chairman of the House Democratic Caucus, and Terri A. Sewell of Alabama, to defend incumbent Democrats against primary opponents.

Moderates have also allied with Shield PAC, founded by Democrats ousted in November from Republican-leaning districts, to push back on efforts to tar all Democrats with the slogans of the left.