As President Trump unleashed a barrage of tweets Wednesday to declare Fox News Channel “dead” and proclaim “Massive FRAUD” in the 2020 presidential election, some of his foes on Capitol Hill gathered in conference room 385 of the Russell Senate Office Building for a quiet celebration.

Sen. Joe Manchin III (D-W.Va.), one of the group’s ringleaders, brought a Mason jar filled with 170-proof moonshine, offering what he called his “farm fuel” to the assembled roomful of socially distanced senators. The bipartisan group led by eight centrists was just days away from securing passage of an approximately $900 billion economic relief package that had been stalled for months.

“I did not partake,” Sen. Mitt Romney (Utah), who is Mormon and was the 2012 Republican presidential nominee, said of Manchin’s moonshine. “But he did offer it to all.”

For about nine months, direct talks between senior Democratic and Republican leaders did not produce legislation to address the nation’s growing economic calamity. Both sides agreed on the urgent need for more aid, but discussions between congressional Democrats and White House officials repeatedly broke down amid bickering, finger-pointing and political gamesmanship. The conditions in the country only worsened in the fall, as a spike in coronavirus cases and deaths led to a surge in new economic pain.

After passing a record $3 trillion in economic relief this spring, Congress went months without a new aid package even as the coronavirus pandemic worsened. (The Washington Post)

The legislative logjam held until a group of rank-and-file senators — led by Romney and Manchin, as well as Sens. Mark R. Warner (D-Va.), Lisa Murkowski (R-Alaska) and Susan Collins (R-Maine), plus a like-minded group of House centrists — produced a $908 billion legislative framework forged over at least a dozen Zoom and dinner meetings, as well as dozens of phone calls between members.

The original proposal was modified by congressional leaders — they dropped $160 billion in aid to state and local governments and added direct stimulus checks, for example. But the bipartisan framework largely mirrors the bill that passed Congress on Monday. President Trump was expected to sign it into law until signaling Tuesday that he wanted Congress to increase the amount of stimulus checks.

The lawmakers involved in the effort are now hoping that their new coalition could form the basis for future collaborations, and they have received a vote of confidence from President-elect Joe Biden, who said Sunday that he was “heartened to see members of Congress … reach across the aisle, and work together.” Vice President-elect Kamala D. Harris, still a senator from California until her expected resignation before the Jan. 20 inauguration, was among the 92 senators who voted in support of the measure late Monday night.

“This is a model for the challenging work ahead for our nation,” said Biden, a former six-term senator who has pledged to rekindle the lost art of congressional dealmaking.

Senate Majority Leader Mitch McConnell (R-Ky.) also had words of praise: “When you have divided government, I think what the American people are saying, we know you have some differences, probably a lot of them. But why don’t you look for the things you can agree on and do those?” he said.

The Washington Post interviewed more than a dozen members of Congress, as well as numerous legislative aides, lobbyists and policy experts closely involved in the crafting of the relief package for this article.

Despite the relief it offers, many economists say the package will not be sufficient to buttress the nation’s economy through the next year. The decision to cap the bill around $900 billion paved the way for its passage but will limit how much suffering it prevents. The measure’s unemployment provisions, for instance, will mostly expire in March — months before the coronavirus vaccines will be widely distributed. It has no direct money for states and cities, despite severe revenue shortfalls in many parts of the country. The number of coronavirus cases is expected to reach highs this winter, but lawmakers could not rally around a bill the size of the $2 trillion Cares Act, which was signed into law in March. They couldn’t even support a measure half that size.

The bipartisan group took criticism from both sides, with Sens. Bernie Sanders (I-Vt.) and Josh Hawley (R-Mo.) excoriating the Romney-Manchin effort for leaving out stimulus payments for millions of American households.

“This bill will offer some limited relief. And it was a fight,” said Sen. Ron Wyden (Ore.), the ranking Democrat on the Senate Finance Committee, who helped secure some expansions of unemployment insurance but expressed disappointment about its duration and the exclusion of as many as 13.5 million adult dependents from the $600 stimulus payment. “The Senate Republicans had a united position in hiding behind their spending caps, because that made it harder to include improvements for the American people.”

Six conservative Republican senators also ultimately voted against the bill, with Sen. Rick Scott (Fla.) describing it as “harm to future generations of Americans” by increasing the national deficit.

The prospect of governing from the center will continue to be daunting. The moderates’ success in driving the stimulus impasse to a conclusion came after the collision of an unusually bitter partisan standoff with a grave moment of national crisis, overlaid with the raw political calculations of an election year and a disengaged president.

The deal was ultimately buttoned up and delivered in high-stakes negotiations among the top four congressional leaders, who each zealously guard their parties’ prerogatives — and their own power.

McConnell said the bipartisan group made a “helpful contribution” — if only to show that Democrats could accept a package under $1 trillion. House Speaker Nancy Pelosi (D-Calif.) and Senate Minority Leader Charles E. Schumer (D-N.Y.) embraced the group in early December — but only after they perceived it as a way to isolate McConnell and force Republicans to accept some of their key demands.

Senate leaders on both sides of the aisle each blamed the other for the long stint between the last coronavirus relief package and the deal reached Dec. 20. (U.S. Senate)

The bill came together under the immense pressure of a worsening pandemic, a potential government shutdown and looming deadlines that, if left unaddressed, could have severely hurt the U.S. economy. As the coronavirus raged with renewed intensity nationwide, lawmakers on Capitol Hill began hearing from increasingly desperate restaurant owners, jobless Americans, flight attendants and others clamoring for more government aid. It also became coupled with a year-end “Christmas tree” of congressional lawmaking, part of a 5,593-page bill that included everything from tax giveaways for corporate interests to surprise medical billing legislation and year-long appropriations for federal agencies.

But the political dynamics initially appeared stuck. McConnell floated a package worth nearly $1 trillion over the summer, reflecting the positions of his fiscally conservative conference. It showed how Republicans had little appetite for big spending bills as the election approached. Pelosi and Schumer, meanwhile, held firm in demanding a multi-trillion-dollar deal — even in the immediate aftermath of an election that delivered a mixed result. Biden’s presidential victory was coupled with a shrinking House majority for Democrats, and control of the Senate appeared uncertain pending two Jan. 5 runoff elections in Georgia.

By mid-November, rank-and-file lawmakers in both parties realized that something had to give. This included several of the Republican senators most frequently at odds with Trump, such as Romney, as well as Democrats from purple states and districts who felt out of step with the leftward drift of their party.

The group’s discussions started over Italian food at Murkowski’s house on Capitol Hill, where they cast about trying to find an overall number that could form the basis for a compromise. Democratic lawmakers eyed $1.4 trillion — halfway between the $1.8 trillion the White House offered before the election and the sub-$1 trillion bill McConnell offered over the summer.

But the Republicans in the room countered that the White House position was now irrelevant — $1 trillion was the most the party could accept. Sen. Richard J. Durbin (D-Ill.), the minority whip and the only member of party leadership in attendance, suggested an opening presented by Biden’s election: Democrats could think of the bill as a temporary measure buying three months of additional relief rather than something designed to right the entire economy in one fell swoop.

Romney described that pitch as a key “breakthrough,” and talks continued from there. Manchin was aware that a similar group in the House — the bipartisan Problem Solvers Caucus — had put together its own framework earlier in the fall, and he contacted its Democratic co-chairman, Rep. Josh Gottheimer (N.J.). Collins, meanwhile, contacted the group’s GOP co-chairman, Rep. Tom Reed (N.Y.), and the two House members became a fixture in the marathon meetings that ensued.

As the negotiations proceeded from Nov. 24 through Dec. 6 — often on Zoom calls lasting several hours — the lawmakers began to become deeply invested in the group’s work. Multiple lawmakers and aides described it as their most meaningful legislative experience, sometimes through decades in Congress. Warner in particular credited Murkowski for “continuing to drive home the point that was bigger — that this was really important to show we’re not oblivious and we’re not idiots, and that there’s enormous pain out there even if leadership is just giving speeches against each other.”

“It’s not made-for-cable news,” said Gottheimer, who attended one three-hour Zoom meeting while sitting outside an Interstate 95 rest stop named for Biden. “It’s not as sexy as, you know, screaming at one another. But I walked away thinking that this is exactly what people want us to do, which is to sit down and don’t leave the room until you figure it out. We didn’t leave the Zoom until we figured it out.”

The group made progress in part as congressional leaders receded from discussions. At one point in deliberations, Romney contacted McConnell to brief him on the group’s work. McConnell did not discourage Romney’s efforts, but also expressed little interest in learning more.

“He didn’t give us any input, didn’t tell us anything to include or not include,” Romney said. “He didn’t express interest in hearing the blow-by-blow.”

Similarly, around the same time, Democratic senators involved in the bipartisan negotiations briefed Biden’s team on the sensitive deliberations and requested feedback. The Biden officials kept their distance from the centrist lawmakers’ work.

“They did not ask for the details because they did not want to know the details,” said one Democratic senator involved in the negotiations, who spoke on the condition of anonymity to describe sensitive talks. “They didn’t want to own it, for better or worse, because when they saw the progressives afterward, they could say: ‘We didn’t know.’ ”

By the time the top four leaders met in person to discuss a deal for the first time on Dec. 15, the bipartisan group had delivered its most valuable contribution: a rough framework and momentum to go with it.

Inside the room, the squabbling began — with Republicans seeking to subtract the $160 billion in disputed state and local funding from the baseline, while Democrats sought to keep the bill at $900 billion. Ultimately, the two parties settled on the higher number — keeping a $300 monthly federal unemployment supplement and adding $600 stimulus checks, one of the few details Trump cared about.

In the following week, hiccups and false starts occurred — and one moment of panic when it seemed as though an obscure paragraph could scuttle the whole bill.

Sen. Patrick J. Toomey (R-Pa.), an influential fiscal conservative, had insisted for months on shutting down special lending programs created by the Federal Reserve at the height of the pandemic-induced financial trauma. But he also wanted to put new guardrails on future Fed programs — alarming Democrats who viewed it as an attempt to handcuff Biden and erode the Fed’s historic independence.

Behind the scenes, Schumer — a veteran of the House and Senate banking committees — worked the phones with Fed Chair Jerome H. Powell and former chairman Ben S. Bernanke, raising alarms with them and alerting other Democrats to put up a fight.

By Saturday afternoon, the tussle threatened to take down the legislation until Manchin, Romney and several other senators intervened to try to broker a compromise. Toomey disappeared into Schumer’s office, and by the end of the night, the two men agreed on a compromise to allow the bill to move forward.

Lawmakers may not be as eager for a compromise next time, and divisions over further relief are already emerging. Biden intends to seek another aid package after his inauguration next month, which could very well spur another partisan standoff.

“I don’t rule it out or rule it in,” McConnell said Monday when asked about another package, noting that he plans to hold firm in demanding the liability protections that even the bipartisan group found it difficult to agree on.

Romney said the group has informally begun conversations about whether it could coalesce around another bipartisan effort, citing the national deficit, climate change and immigration as possible areas of future work. The final package mirrors the Romney-Manchin proposal in dozens of ways, down to the precise amount of money allocated for schools, small business aid, the hungry and distressed renters. But Romney acknowledged the likelihood that the momentum for this package would be hard to replicate.

“There was a big river that wanted to push this through, but there was a logjam that kept it from happening. We were one of the things that helped it come off — and, boy, it flowed,” Romney said. “On some of our other issues, we may be able to get together and get things sorted out. But I’m not sure we have a big river behind us.”