On the day President Biden’s first attempt at a bipartisan infrastructure deal collapsed, he dialed up a Republican senator he saw as a potential negotiating partner for a renewed push.

In that June 8 phone call, Biden told Sen. Bill Cassidy (R-La.) that he wanted a public works agreement with Republicans in the neighborhood of $600 billion. More notably, Biden showed deep interest in provisions on energy resiliency that Cassidy had been working on for weeks.

That embrace of a favored provision hit home with Cassidy. “The president made it clear that that was essential for him,” the senator said. “Since the president had said it must be there, obviously that was very helpful.”

Cassidy would ultimately become one of five Senate Republicans, who, along with five Democrats and the White House, reached an agreement last week on a sweeping infrastructure package that includes $550 billion in new spending to revitalize the nation’s roads, strengthen public transit, repair water systems and expand broadband networks.

The Senate on Aug. 1 worked to finalize legislative text to forge ahead with a sweeping $1 trillion infrastructure bill. (Reuters)

The months of arduous negotiations leading to last week’s agreement make up only the first hurdle. In coming days, the package must clear the Senate — where it garnered 67 votes in a recent test vote — and also survive the House, where many discontented liberals see the agreement as inadequate.

Still, the infrastructure talks have served so far as evidence for Biden’s insistence that bipartisanship can prevail even in a virulently divided political atmosphere and that his Senate roots could help him navigate a Republican Party whose voters often do not even acknowledge his legitimate win in November.

Biden’s phone call with Cassidy was only one example of Biden’s contact with Republicans during the talks. He regularly called GOP senators, White House aides say, while presidential counselor Steve Ricchetti was on virtual speed dial on the Republican negotiators’ phones. After he inadvertently angered Republicans by attaching public conditions to the deal, Biden personally phoned Sen. Rob Portman (R-Ohio) to ask how he could quell the uproar.

And as talks reached their critical endgame, he deputized Ricchetti, a longtime friend and adviser, to closet himself with Portman and hammer out the final details.

“I’m working with Democrats and Republicans to get this done, because — while there’s a lot we don’t agree on — I believe that we should be able to work together on the few things we do agree on,” Biden told a crowd of autoworkers in Lower Macungie Township, Pa., last week. “I think it’s important.”

The nearly four months of negotiations with Senate Republicans reflected a markedly different dynamic from Biden’s push for emergency coronavirus relief earlier this year, when the president’s brief negotiations with Republicans were promptly eclipsed by Democrats moving on unilaterally to enact $1.9 trillion in pandemic aid.

On infrastructure, Biden repeatedly made it clear in conversations with Republicans that he was serious about achieving a bipartisan deal, according to interviews with senators, congressional aides and administration officials. His chief emissaries to the Capitol — Ricchetti; Brian Deese, director of the National Economic Council; and Louisa Terrell, Biden’s legislative affairs director — echoed that message as often as they could.

Biden had to walk a balance. Some Democrats were angry at his outreach to Republicans, who they said long ago abandoned any pretense of bipartisanship and steamrolled Democrats when they could.

The Republicans were also torn between competing forces. The party’s pragmatists hoped that by negotiating with the White House, they could avoid a more liberal infrastructure package. But many in the GOP oppose working with Biden at all, and former president Donald Trump is still trying to sabotage the deal.

But even as an earlier set of talks between Biden and Sen. Shelley Moore Capito (R-W.Va.) was grabbing headlines in May, the White House was in touch with a separate group of 10 senators that had begun its own infrastructure discussions, after Portman and Kyrsten Sinema (D-Ariz.) started talking and then brought in other senators.

Biden viewed Portman, who is not seeking reelection, as a good-faith negotiator, and the White House has long paid considerable attention to the enigmatic Sinema, a vital swing vote for the president’s agenda.

Meanwhile, the president found himself talking to Cassidy about infrastructure during a presidential trip to his home state of Louisiana and began seeing him as a potential collaborator as well. Through their regular legislative affairs outreach, White House staffers had already alerted Biden to Cassidy’s bipartisan work with Rep. Josh Gottheimer (D-N.J.) to make the nation’s energy system more impervious to natural disasters.

Cassidy is a staunch Republican, not generally viewed as a moderate, but he has been willing to work with Democrats, and “you leave no stone unturned” when it comes to prospective negotiating partners, said one White House official, speaking on the condition of anonymity to discuss internal strategy.

Once Biden’s talks with Capito collapsed, the White House turned its attention fully to the group of 10 senators, which until then had kept an intentionally low profile.

Ricchetti, Deese and Terrell began regularly showing up at the Capitol. As the 10 senators sat around a wide table, the three White House officials would intersperse themselves among them, allowing for side conversations on what senators were hearing from constituents back home.

“They wanted to be supportive but not actively engaged in owning all the outcomes,” Sen. Mark R. Warner (D-Va.) said of Biden’s team. Over time, however, “it became evident that to make sure we got all the Democrats, they had to own more of the product.”

Red lines were made explicit: The GOP refused to reverse any of the tax cuts enacted under Trump. Biden would not hike taxes on those making less than $400,000 a year, which ruled out raising the gas tax. Spending from Biden’s coronavirus relief package would go untouched.

But both sides took those limitations as a starting point, not an end.

“You can tell the difference between an adversarial negotiation and a collaborative one,” said Sen. Mitt Romney (R-Utah). “In this case, when one side had a problem, the other side tried to solve the problem, rather than to walk away from the table.”

While Ricchetti, Deese and Terrell were furiously negotiating details at the Capitol, Biden was briefed multiple times a day at the White House and repeatedly hopping on the telephone, according to a second senior White House official.

Top White House aides also held daily meetings to gauge progress, as did members of the “jobs cabinet” — the secretaries of commerce, transportation, energy, labor, and housing and urban development. On those calls, White House officials and the Cabinet secretaries would swap intel on what lawmakers were thinking and identify stumbling blocks.

Of the five Cabinet members, Commerce Secretary Gina Raimondo was the most closely involved in negotiating with Republicans, striking an agreement with Sens. Susan Collins (R-Maine) and Jeanne Shaheen (D-N.H.) on a broadband provision, after numerous meetings and lengthy text chains.

The broad infrastructure deal was announced with great fanfare in June outside the White House. But many details remained unresolved, and the push to promote the effort in the Senate only intensified, with Terrell’s 25-member shop holding more than 330 meetings or phone calls with lawmakers and their top staffers. The White House legislative affairs office — in tandem with other White House divisions and administration agencies — held more than 60 congressional briefings on the agreement.

By that point, a working relationship had developed. “If we’re speaking to the White House officials, I always felt as if we were getting straight scoop,” Cassidy said.

But as soon as the agreement came together, it almost fell apart.

Biden, speaking triumphantly to reporters hours after announcing the deal, said he would not sign it unless it was accompanied by a separate package that encompassed only Democratic priorities. It was an effort to placate liberals afraid that the bipartisan deal abandoned their goals.

Collins saw a news alert about Biden’s comments — effectively a veto threat against his own deal — flash across her phone as she waited at Reagan National Airport for a late-night flight to Maine. Before boarding, Collins called Ricchetti, who promptly answered.

“I remember I was so shocked because that was completely contrary to what we had explicitly talked about in the Oval Office and then at the press conference right afterwards,” Collins said.

Early the next day, Ricchetti called Collins back, telling her he was working on getting the agreement with Republicans back on track. Biden was also working the phones, calling Portman and asking what he should say to reassure GOP senators, according to a Republican close to the talks. The president ultimately issued a lengthy statement backtracking on his comments.

Even so, more than a month would pass from the announcement of the initial framework to last week’s finalization of the deal. In that time, several eruptions threatened to unravel the entire effort.

The administration and GOP senators haggled in recent days, for example, over the structure of an “infrastructure bank” designed to generate investment in big projects through public-private partnerships. Ultimately, the administration took the idea off the table, leaving Republicans “baffled,” Collins said. The White House declined to comment on why it did so.

In the final days before announcing last week’s final breakthrough, senators and the White House delegated the last stretch of talks to two seasoned Washington operators: Portman and Ricchetti.

It was a conscious decision, the first senior White House official said, with Biden wanting to avoid too many cooks in the kitchen at a pivotal moment.

So the two men — both Ohioans whose joint history dates to at least the 1990s, when Ricchetti worked for President Bill Clinton and Portman was a House member — camped out for nine hours Tuesday night in Portman’s Senate conference room, where a kayak and several Ohio sports jerseys hang on the walls. Those intensive talks helped resolve one of the final sticking points — how much to spend on public transit.

Even with last week’s successful Senate vote to advance the package, weeks if not months lie ahead before Biden will be able to sign it into law, assuming it survives at all.

If the Senate passes the bill in coming weeks, it will have to pass muster in the House, where Speaker Nancy Pelosi (D-Calif.) has said she will not allow it to reach a vote until the separate Democratic-only package has cleared. And the process on that latter legislation is likely to be longer and more complicated even than the bipartisan talks, meaning there is no guarantee either bill will pass.

But Biden and others who say the parties can still cooperate in the post-Trump era claim the process so far validates their view. And how the White House nurtured trust with a group of pivotal Republicans offers some instructive clues on how it could lean on those relationships for other efforts.

“The president and his team have to be willing to invest the time and say no to the left — the far left — and Republicans have got to be willing to say no to the far right,” Collins said. “This really was built center-out.”

Mike DeBonis and Tony Romm contributed to this report.