House Democrats on Thursday delayed a vote on an approximately $1 trillion proposal to improve the nation’s infrastructure, a dramatic reversal after hours of negotiations that marked a major setback for President Biden’s economic agenda.

The decision came after House Speaker Nancy Pelosi (D-Calif.) and other Democratic leaders strained late into the night to try to repair the schisms among their own moderate and liberal ranks, whose distrust of each other turned the public-works bill into a political bargaining chip in a fight over the full array of new spending that Biden seeks.

The source of the Democratic stalemate was a second, roughly $3.5 trillion package that proposes to expand Medicare, combat climate change and boost federal safety-net programs, all financed through tax increases on wealthy Americans and corporations. To safeguard the initiative from cuts at the hands of centrists, including Sens. Kyrsten Sinema (D-Ariz.) and Joe Manchin III (D-W.Va.), liberals threatened to oppose the infrastructure bill that the moderate duo originally helped negotiate.

Pelosi had spent the day huddling with Democrats’ warring factions in private meetings, while the White House labored to work with Sinema and Manchin on a spending deal they could support. But the flurry of outreach, sometimes from Biden personally, failed to bring the two camps together — generating acrimony among Democrats’ own ranks.

Manchin emerged from one of those gatherings with the president’s top aides shortly before 10 p.m. and asserted that there needed to be dramatic cuts to liberals’ most prized priorities. He said that any tax-and-spending measure should be much less than the $3.5 trillion price tag that many other Democrats initially sought.

“We’re in good-faith negotiations, we’ll continue in good-faith negotiations,” Manchin stressed to reporters as he left the Capitol.

Absent a deal, the political dynamic threatened to leave Pelosi facing a difficult choice in the hours ahead. If she put the infrastructure bill on the floor, she would risk an embarrassing defeat. But if she held the bill back, it could upset moderates who had demanded the vote in the first place. The speaker chose the latter option, something liberals throughout the day had demanded.

“A great deal of progress has been made this week, and we are closer to an agreement than ever,” White House press secretary Jen Psaki said in a statement. “But we are not there yet, and so, we will need some additional time to finish the work, starting tomorrow morning first thing.”

After raising the debt limit for decades, Republicans in recent years have leveraged it to enact spending cuts while also threatening government default. (JM Rieger/The Washington Post)

The uncertainty on Capitol Hill marked a sharp contrast from what lawmakers had hoped would be a more joyous occasion for Biden, delivering him his first bipartisan victory. And it exposed an ever-growing sense of distrust among Democrats that only added to the challenge Pelosi and other leaders face in governing in a time of narrow majorities.

For the party, though, the consequences for inaction remain great. Democrats believe they seized control of the White House and Congress in the 2020 elections in part by championing Biden’s campaign pledge to “build back better” through sizable new investments in the country’s inner workings. A failure to deliver could damage their standing in the eyes of voters ahead of the midterm elections in 2022, all the while delaying investments and reforms that Biden and his allies say are already long overdue.

“The majority of the agenda that the president ran on that delivered us the House, the Senate and the White House is in the Build Back Better agenda,” said Rep. Ilhan Omar (D-Minn.), referring to both the infrastructure plan and the House’s $3.5 trillion tax-and-spending proposal. “If we fail to deliver that promise, we have failed the American people.”

The stakes also were top of mind for Sen. Mark R. Warner (D-Va.), who helped craft the infrastructure bill as well as the framework for what became the House’s $3.5 trillion package. Citing the closely watched gubernatorial race in Virginia, where some residents are “real-time voting,” the centrist Democrat stressed Thursday: “It doesn’t help us in Virginia if we can’t get the infrastructure bill done today.”

The House began considering the infrastructure measure on Monday, as Pelosi looked to deliver on a promise she made to moderates in her party to sidestep an earlier revolt. Those House centrists, led by Rep. Josh Gottheimer (D-N.J.), had projected a measure of confidence in recent days, believing that the speaker still can whip the votes — and that some Democrats largely were bluffing when they say they plan to vote against the president’s agenda.

Liberal-leaning lawmakers, meanwhile, had called for delays and blasted the intended Thursday vote as arbitrary, as they hoped to finalize the second spending package — and perhaps even secure a Senate vote on the measure. But doing so risked sparking a rebellion among centrists, prompting some moderates to issue their own stark warnings to Pelosi as tensions mounted.

“Leadership made a very clear promise to people that this bill was going to be put on the floor for a vote,” said Rep. Kathleen Rice (D-N.Y.). “And if they go back on that, that’s a breach of trust I don’t know if this caucus is going to be able to recover from.”

Speaking to reporters earlier Thursday, Pelosi initially swatted away the threats from her own caucus, stressing that she still planned to vote on infrastructure. She then embarked on a flurry of meetings with the disparate factions of her party as she struck a defiant yet upbeat note: “I’m only envisioning taking it up and winning it,” she said at a news conference.

Biden and White House aides, meanwhile, continued to try to negotiate a deal with Sinema and Manchin to loosen the liberals’ opposition. Psaki said at her daily press briefing that talks are ongoing, adding: “We’re working toward winning a vote tonight.”

But as the night dragged on, the political climate became only more complicated.

Lawmakers in the Congressional Progressive Caucus expressed confidence they controlled enough votes to scuttle the infrastructure bill. “We’re in the same place we’ve always been,” predicted Rep. Pramila Jayapal (D-Wash.), the leader of the group, where about half of the 100-member bloc previously has threatened to oppose the infrastructure proposal. “We will not be able to vote for the infrastructure bill until the reconciliation bill has passed,” she said.

Talks between centrists and the White House once again appeared to produce no result as well. Manchin and Sinema still refused to waver in seeking massive cuts to House Democrats’ $3.5 trillion package, including limits on that money that would scale back the eligibility of things such as free community college. Neither appeared newly supportive of the exact tax increases Biden has proposed, either.

Instead, Manchin doubled down in a news conference, stressing that he supports $1.5 trillion in spending, far less than liberals seek, as he said Democrats can’t pursue “everything at one time.”

“I’ve never been a liberal in any way, shape or form,” Manchin said. “I don’t fault any of them who believe that they’re much more progressive and much more liberal. God bless ’em. … For them to get theirs — elect more liberals.”

In a statement Thursday, a spokesman for Sinema declined to share more about her positions, other than to say she had communicated her views directly with the White House. “While we do not negotiate through the press — because Sen. Sinema respects the integrity of those direct negotiations — she continues to engage directly in good-faith discussions with both President Biden and Sen. [Charles E.] Schumer to find common ground,” said spokesman John LaBombard.

Neither Manchin nor Sinema broached the issue as they attended a private lunch for Democrats early in the day. But Manchin’s words in particular resonated across the Capitol, infuriating liberals, who saw a generational opportunity to secure long-sought spending priorities now in jeopardy.

“It would mean decimating vital, important programs for working families,” warned Sen. Bernie Sanders (I-Vt.), the architect of the $3.5 trillion budget plan, as he ticked off the effects of the centrists’ proposed cuts. “Obviously we could not do for the children what has to be done, we cannot do for seniors what has to be done. We would not be able to do paid family and medical leave.”

“The planet is at stake,” he continued. “We got four or five years before there is irreparable harm, and clearly $1.5 trillion would make it absolutely impossible for us to do what has to be done.”