In the center of all this was Biden himself, a career senator who aides say is fully aware that the success of his first term as president is inextricably tied to the success of this infrastructure bill. 

Throughout the spring and summer, Biden traveled across the country, touting the merits of the infrastructure bill in a series of highly publicized presidential visits. 

Back in Washington, Biden personally waded into the legislative drama at decisive moments. 

In May and June, the president hosted both Republican and Democratic senators at the White House for candid, private meetings in the Oval Office to talk about what they needed to see in the bill in order to support it.

Some senators needed extra hand-holding. Biden met at least three times one-on-one with Arizona’s Kyrsten Sinema, a centrist Democrat who insisted from the start that the bill be bipartisan and who later helped craft the eventual compromise legislation. 

After one meeting, Sinema said that she and the president had discussed, among other things, the importance of rural broadband expansion to her home state.

The bill that passed on Tuesday provides $65 billion to expand broadband access to underserved communities. 

But it wasn’t just the centrists Biden courted. 

In mid-July, the president met at the White House with progressive Sen. Bernie Sanders, I-Vt., his onetime rival for the Democratic presidential nomination. 

At the time, Sanders, who chairs the powerful Senate Budget Committee, was publicly calling for a much bigger social safety net package than what most moderate Democrats felt they could support, somewhere in the range of $6 trillion, nearly double what the White House was considering.

Outside of Washington, the mere mention of a $6 trillion Democrats-only bill was enough to make some vulnerable Democrats reconsider whether to support the infrastructure bill or the social safety net reconciliation bill.

Biden needed to reach an understanding with Sanders quickly to stave off any dissent within the ranks.

Sanders also wanted something specific from the White House: The president’s support for a plan to expand Medicare coverage to include dental, vision and hearing care.

A day after Sanders and Biden met on July 12, Democrats unveiled their long-expected social safety net plan. 

Most of the plan was based on promises Biden had made to voters during his 2020 presidential campaign. But there was one last-minute addition: Medicare coverage for dental, vision and hearing. 

Following Tuesday’s vote, Biden said there was a lesson to be drawn from the way the infrastructure bill had been negotiated.

“The lesson learned is being willing to talk and listen,” he told reporters at the White House. “Listen. Call people in. And I think the lesson learned is exposing people to other views.”

“That’s why, from the beginning, I’ve sat with people and listened to their positions — some in agreement with where I am and some in disagreement. So I think it’s a matter of listening; it’s part of democracy,” said Biden.

As Biden and his fellow Democrats worked to unite behind the pared-down infrastructure bill and its sister bill, the $3.5 trillion social safety net expansion, their task was made easier by unique dynamics playing out within the Republican caucus.

One was an unusually large number of Republican retirements announced in the Senate this cycle.

Unlike a typical senator, who is under pressure to win support from his party’s base in order to survive a primary and then to win support statewide in order to be reelected, a retiring senator faces no such pressure.

Retiring senators are free to vote their consciences, without worrying about whether those votes could hurt them on Election Day. 

Of the five Republican senators planning to retire next year, three of them crossed party lines to support the bill.

Ohio’s Rob Portman led the GOP negotiating team, doing more than almost anyone except Biden to get the deal over the finish line. 

Two other retiring Republican senators, Richard Burr of North Carolina and Roy Blunt of Missouri, also threw their support behind the deal at crucial moments. 

Burr signed on in mid-July, helping to answer the question of whether a deal that had been reached by a small cadre of senators could win over a broader coalition. 

Blunt voted for the bill in its first big test, a procedural vote in late July to begin formal debate on the bill. 

But there is still one Republican whose support for the deal likely did more than any other senator’s to ensure the bill’s bipartisan success: Senate Minority Leader Mitch McConnell. 

In his tenure as a leader of Senate Republicans, McConnell has earned a reputation as a grim reaper for Democrats’ pet legislation, always ready to ring the death knell. 

But this time around, McConnell held back. 

Instead of blocking the bill from the outset, as many expected him to do, McConnell tacitly let the negotiations proceed and left the door open to a deal that he would greenlight Republicans to vote for. 

As the summer wore on and the bill progressed through the Senate, the question of why McConnell didn’t kill the deal evolved into a sort of Washington parlor game.

There are several factors likely at play here. 

One is that infrastructure is universally popular with voters, and McConnell knows that as well as anyone. 

“He’s a very pragmatic person. I think he knows that everybody sort of wins if it’s true, hard infrastructure,” said Sen. Kevin Cramer, a North Dakota Republican, in a recent interview with the Associated Press.

Another boon for the bill is the fact that residents of McConnell’s home state of Kentucky will likely see outsized benefits from its provisions, such as federal road projects and expanded rural broadband funding.

Yet another element working in the bill’s favor is the bigger debate within the Senate over the filibuster, the 60-vote threshold needed to advance most legislation through the chamber.

Biden has resisted mounting calls by progressive Democrats to eliminate the filibuster, which critics say is an outdated and fundamentally unfair rule.

For McConnell, letting the infrastructure bill pass with more than 60 votes “is a good demonstration that he can preserve the filibuster and still have meaningful, bipartisan legislation,” Cramer said to the AP. 

“And at the end of the day, he’s got a constituency back in Kentucky that probably looks pretty favorably on it.”