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. Some have backed a new pro-Israel group, Democratic Majority for Israel, determined to thwart the party’s emerging Palestinian rights movement — and defeat left-wing candidates who they say have crossed an unacceptable political line on the Jewish state.

Understand the Infrastructure Bill

    • One trillion dollar package passed. The Senate passed a sweeping bipartisan infrastructure package on Aug. 10, capping weeks of intense negotiations and debate over the largest federal investment in the nation’s aging public works system in more than a decade.
    • The final vote. The final tally in the Senate was 69 in favor to 30 against. The legislation, which still must pass the House, would touch nearly every facet of the American economy and fortify the nation’s response to the warming of the planet.
    • Main areas of spending. Overall, the bipartisan plan focuses spending on transportation, utilities and pollution cleanup.
    • Transportation. About $110 billion would go to roads, bridges and other transportation projects; $25 billion for airports; and $66 billion for railways, giving Amtrak the most funding it has received since it was founded in 1971.
    • Utilities. Senators have also included $65 billion meant to connect hard-to-reach rural communities to high-speed internet and help sign up low-income city dwellers who cannot afford it, and $8 billion for Western water infrastructure.
    • Pollution cleanup: Roughly $21 billion would go to cleaning up abandoned wells and mines, and Superfund sites.

On Friday, yet another centrist group, No Labels, began airing an advertisement backing Representative Henry Cuellar of Texas, one of the nine holdouts on the budget who is being challenged by a young liberal, Jessica Cisneros, in the upcoming primary season. The ad extols him for “fighting for the Biden agenda,” though arguably he is now trying to hold much of it up.

The idea, moderates say, is to inoculate the party from slogans like Defund the Police that were effectively used against swing-district Democrats in November, and stop progressive gains before divisions in the Democratic Party grow as deep as they have been in the Republican Party. The issue is more about tone and cooperation than ideology, said Mark S. Mellman, a longtime Democratic strategist and pollster, who helped found the Democratic Majority for Israel and its political action committee.

“There’s nothing revolutionary about ‘Medicare for all,’ moving to a clean energy economy, a $15 minimum wage,” he said. “There’s a lot of consistency around the general direction of policy. But the rhetoric is different.”

The efforts have left liberals feeling aggrieved and worried that the Democratic establishment is actually hurting the party — by sapping the vital energy of younger voters. Young liberals like Representatives Alexandria Ocasio-Cortez and Jamaal Bowman not only defeated Democratic stalwarts to win their seats in New York, but they have captured the imagination of the next generation, said Waleed Shahid, a spokesman and strategist for Justice Democrats, which promotes insurgent progressive candidates.


Aug. 17, 2021, 6:05 p.m. ET

“The future of the party looks a lot more like A.O.C. than Joe Biden,” he said.

The establishment’s efforts are showing results. One of the left’s political heroes, Nina Turner, lost a House special election primary in Cleveland this month, after Representative James E. Clyburn of South Carolina, the most senior African American in Congress, and Mr. Mellman’s group swooped in to prop up a little-known but more conciliatory candidate, Shontel Brown. In New Orleans, the favored progressive candidate in the race to replace Representative Cedric Richmond, who joined the Biden White House, also lost.

Liberals say the moderates, not the progressives, are now the ones standing in the way of Mr. Biden’s agenda, by provoking the House’s stalemate and threatening the social policy bill in the Senate.