WASHINGTON — Senator Joe Manchin III of West Virginia raised new doubts on Monday about an emerging compromise on a $1.85 trillion climate change and social safety net bill, warning that he had serious reservations about the plan and criticizing liberals in his party for what he called an “all or nothing” stance on it.
Mr. Manchin’s broadside, delivered during an appearance in the Capitol, threatened to upend the Democratic Party’s ambitions to vote this week on President Biden’s top two legislative priorities, even as lawmakers were gathering for what was supposed to be a momentous week for the president’s ambitious domestic agenda.
It came as congressional negotiators were closing in on a final deal on the social policy and climate legislation, which progressives have called a prerequisite to supporting a separate, $1 trillion bipartisan infrastructure bill.
Top officials were hammering out last-minute details of the policy plan, including a program to curb the rising cost of prescription drugs, which had been left out of an outline that Mr. Biden presented on Thursday. Negotiators had all but secured a compromise that would include a $2,000 annual cap on out-of-pocket prescription expenditures for older Americans, according to Senator Ron Wyden of Oregon, the Democratic chairman of the Finance Committee. There would also be price limits on insulin, rebates on drugs whose prices rise faster than inflation and some limited government power to negotiate drug prices.
But Mr. Manchin may well have upset the final push toward passage this week. The substance of his remarks was not considerable; he has raised concerns for months about the fiscal and economic impact of the social policy bill, and other lawmakers have echoed his desire to see its full text and official cost before supporting it. It also reflected similar requests from some House lawmakers, who are set to vote first on the broader social policy bill.
But Mr. Manchin’s tone revived some fears among House Democrats that his vote might not be winnable. Democrats have shrunk their proposal considerably — from $3.5 trillion to about half that size — largely to win his support and that of Senator Kyrsten Sinema of Arizona, another centrist holdout.
Because of the evenly divided Senate, the defection of a single Democrat would tank the social policy and climate legislation, which is central to the president’s domestic agenda. Mr. Biden privately assured House Democrats last week that his outline had the backing of the Senate’s 50 Democrats and independents.
“While I have worked hard to find a path to compromise, it is obvious compromise is not good enough for some in Congress,” Mr. Manchin said on Monday, reading from prepared remarks as he apparently referred to liberals in the House. “It’s all or nothing, and their position doesn’t seem to change unless we agree to everything. Enough is enough.”
He warned, “I’m open to supporting a final bill that helps move our country forward, but I’m equally open to voting against a bill that hurts our country.”
White House officials and leading Democrats rushed to downplay Mr. Manchin’s remarks, insisting that the package was still on track. They worked quickly to refute his fiscal concerns, issuing statements that described how the legislation was written to be fully financed and would help create jobs. They cited a letter from 17 Nobel Prize-winning economists who predicted that the plan would ease inflationary pressures in the long term.
But some Democrats worried aloud that the senator’s complaints had further inflamed mistrust over a fragile accord in the final stages of negotiation.
“You don’t want to keep throwing up roadblocks — if you do, it’ll never be passed,” said Senator Jon Tester, Democrat of Montana, who helped negotiate the infrastructure bill. Asked if liberals had made a mistake in opposing a planned vote on that bill last week, Mr. Tester said, “of course, but I think Joe made a mistake today by going out and making the news conference.”
Mr. Manchin found fault not only with the overall price tag, but the way the bill is structured. Its authors have phased in some policies over time and abruptly ended most of the programs — some of them after a single year — in hopes of showing that over 10 years, the plan would not raise the deficit.
But proponents freely admit that they hope that many of those programs will be extended by future Congresses, a common strategy under budget rules but one that Mr. Manchin called dishonest gimmickry that he said would threaten the future of Social Security and Medicare. (Those programs are financed through dedicated trust funds, which are not directly affected by the bill.)
Mr. Manchin also showed personal pique, condemning House liberals who had refused to vote for the infrastructure measure without a final deal on the details of the domestic policy plan.
“Holding that bill hostage is not going to work to get my support of what you want,” he said, though he declined to answer questions, including about how much more time he needed to assess the bill.
The infrastructure bill, which Mr. Manchin helped craft as a key negotiator, also has its share of budget chicanery. Nonpartisan estimates said that it would add $256 billion to the deficit over 10 years, less than half the new spending accounted for in the bill.
Several lawmakers, including the liberal ones who had withheld their votes for the infrastructure bill, projected confidence in a final triumph sooner rather than later, despite Mr. Manchin’s comments.
“I am going to trust the president, our members are going to trust the president, and we are going to do the job that we need to do,” said Representative Pramila Jayapal of Washington, the chairwoman of the Congressional Progressive Caucus, adding that she would support votes on both bills once the text was finished.
“Joe Manchin does not get to dictate the future of our country,” Representative Cori Bush, Democrat of Missouri, said in a statement. “I do not trust his assessment of what our communities need the most.”
Congressional negotiators pushed forward with efforts to polish the framework that Mr. Biden laid out.
Like much of the climate and social policy bill, one of the final pieces of the puzzle — a prescription drug measure — is likely to be considerably less ambitious than initially conceived. Medicare would not have broad powers to negotiate prescription drug prices, but would be given those powers over some medicines delivered as outpatient services, like chemotherapy drugs, and a limited number of medicines procured at neighborhood pharmacies.
Most of the savings for older Americans would come from a cap on out-of-pocket expenditures and a requirement that pharmaceutical companies give the government rebates on drugs whose prices rise faster than inflation. The regulation of drug price increases would apply to all Americans, not just those in Medicare.
Mr. Biden’s framework omitted any mention of prescription savings, infuriating some Democrats, animating the older Americans’ lobby AARP and prompting late negotiations that lasted through the weekend.
“We all went from disappointed to just incensed over the last week,” said Representative Angie Craig, Democrat of Minnesota, who won a Republican district in 2018. “A lot of attention is received by the progressives, but for the majority makers who took the House back for Democrats, this is what we ran on.”
The omission surprised lawmakers and lobbyists alike, since Ms. Sinema had been negotiating a compromise with the White House on the issue.
Representative Scott Peters, Democrat of California, whose legislation had served as a template for the discussions between Ms. Sinema and the White House, said that while Democrats might be disappointed about the failure of their decades-long push for broader government negotiations over drug prices, his plan would make a difference for consumers.
Staying with the status quo, he said, “makes no sense at all.”
The latest proposal adds some drugs purchased at retail pharmacies but would not affect most of the expensive prescription drugs currently taken by Medicare patients.
Many Democratic lawmakers ran on a promise to lower prescription drug prices, a popular message supported by majorities of both Democratic and Republican voters. But that pledge has encountered strong resistance from the powerful pharmaceutical industry, which has been spending millions in television advertisements and deploying lobbyists to Capitol Hill to plead its case.
“Just because there are pharmaceutical lobbyists around every corner doesn’t mean we should be stopped from doing the right thing,” Senator Amy Klobuchar, Democrat of Minnesota, said on Monday, urging her colleagues to buck up.
The proposal being discussed would address a major problem for some seniors by putting a limit on how much they could be asked to spend on their drugs in a year. No such limit currently exists, leaving some patients paying $15,000 a year or more.
But the provisions to lower drug prices would be limited. The proposal would allow the secretary of health and human services to negotiate prices of a small fraction of drugs.
Democrats were also holding out hope that some form of immigration relief could make it into the final package.
Senator Richard J. Durbin of Illinois, the No. 2 Senate Democrat, said they planned to meet with the parliamentarian as early as Tuesday to discuss their backup plan, which would expand the homeland security secretary’s authority to grant a temporary status known as parole to undocumented immigrants who have lived in the country for a decade, providing them with work permits and shielding them from deportation.
Luke Broadwater contributed reporting.