He was an arm-draping pol as a senator. He hung out in the Senate cloakroom chatting up legislators as vice president. He pitched himself during the presidential campaign as someone who could “get people working together” and lower the temperature in a Washington overheated by Donald Trump.

Now, after his first full week as president, Joe Biden is coming face to face with the potential limitations of his ability to work across the aisle as he pushes for a $1.9 trillion coronavirus relief bill that is the first big test of his tenure.

Republicans are balking at the price tag and Democrats are sending signals that they’re willing to push the bill through without GOP help as Biden’s campaign pitch to be a deal-maker appears to be giving way to the reality of a Senate that does not resemble the one he once inhabited.

In a nod to reality, Biden told reporters on Friday: “I support passing COVID relief with support from Republicans if we can get it. But the COVID relief has to pass — no ifs, ands or buts.”

The White House has not given up hope of landing some GOP support for the package, and Biden’s call list bears that out. But some of Biden’s courtship is also directed at members of his own party to make sure a deal gets done.

He has called Sen. Susan Collins of Maine several times since his inauguration, and the moderate Republican says she has a “closer relationship” with Biden than she did with Trump.

Biden has made repeated calls to senators in his own party, including two centrists — Joe Manchin of West Virginia and Kyrsten Sinema of Arizona — who have expressed some concerns about the package, according to three people familiar with the calls who spoke on condition of anonymity because they were not authorized to publicly discuss the private conversations.

A retail politician who never misses a chance for small talk or schmooze, Biden has been penned in somewhat by the pandemic, which limits the face-to-face interactions on which he thrives. But there’s still his peerless phone book, built over four decades of dealing with senators on both sides of the political divide.

“When he decides to make one of those calls, he doesn’t really require a call sheet, a sheet that tells him exactly what to say to a member of Congress and how to outline the bill,” White House press secretary Jen Psaki said in an interview on MSNBC. “He knows. He’s known a lot of these people for decades.”

Claire McCaskill, a former Democratic senator from Missouri, says Biden is “workman-like in terms of his outreach and it was not unusual for me to run into Joe Biden in the Senate cloakroom when he was vice president” to Barack Obama.

“He burned up the phone lines,” McCaskill said. “Obama was terrible at that part of the job, while Biden was good at it, to both parties.”

Having spent 36 years in the Senate and eight as vice president, Biden made bipartisan outreach a central promise, even when many in his party argued that Republicans no longer were interested in working across the aisle.

Biden’s most notable deal-making success came in the Obama-era fiscal showdowns during the rise of the tea party Republicans. The landmark agreements locked in tax and spending cuts for a decade — and soured some progressive Democrats on Biden’s brand of compromise.

As vice president, Biden was a trusted emissary to Capitol Hill for Obama, who had served just four years in the Senate.

Biden arrived as a presence in the halls of Congress at several critical junctures. He helped cut a 2010 deal to prevent the expiration of Bush-era tax cuts, then negotiated on the landmark Budget Control Act of 2011 that slashed spending and walked the country back from the 2012 “fiscal cliff” of looming tax increases and budget reductions.

“Biden’s chief virtue as a negotiator is the understanding that ‘Look, you have politics on your side, I have politics on my side, we both have to live within our political constraints,’” said Rohit Kumar, former deputy chief of staff to Senate Republican leader Mitch McConnell of Kentucky. “His pitch: ‘I know there are certain things you can’t do and I am not going to make them deal breakers. We have to get a deal I can sell, a deal you can sell.’”

As senator, Biden also prized his relationships with colleagues, even though his nightly commute home to Delaware cut into his ability to socialize with other lawmakers.

“Well, I don’t want to ruin him, but he did work with us on occasion,” said former Senate Majority Leader Trent Lott, R-Miss.

Lott said Biden was not someone he recalls as often being in the room when Senate leadership was trying to work out a deal on major bills. But Lott pointed to two major instances when he was: the 1994 crime bill and the 2002 Iraq War resolution, a pair of measures for which Biden has since expressed regret.

Still, Lott said Biden’s relationship with McConnell was real and could pay dividends again.

“They worked out an agreement that basically is what they’ve been working off ever since,” Lott said. “Somebody in the media referred to Biden then as the McConnell whisperer.”

Still, the Senate has changed markedly since Biden first joined decades ago, with different skills now in currency as senators gain status on social media, raise money beyond their home states and spend less time socializing with one another in Washington.

Biden’s style of old-school, one-on-one cajoling may be less persuasive for senators from either party who cultivate their own brands and don’t necessarily rely on proximity to presidential power to raise their profiles.

And, of course, policy matters. The parties are more split than ever over the legislative remedies for the nation, a partisan divide that political scientists see as on par with the rifts of the Civil War era.

Biden aides worry that Republicans will continue to balk no matter how many personal phone calls they get from the president or post-pandemic invitations they receive to high-profile events at the White House.

Their boss may be the last one to buy in to that.

“There’s people who say you can’t work with the other side,” Biden said a year ago. “And if that’s the case, prepare your children for a totally different U.S., a totally different world. I don’t believe it.”