President-elect Joe Biden will have his work cut out when dealing with politicians on Capitol Hill which is much changed since he served there.
The club-like atmosphere that Mr Biden knew so well during his 36-year Senate career is gone with partisanship firmly entrenched.
The election results have not dealt him a strong hand to pursue his legislative agenda, with Democrats’ poor performance in down-ballot races likely leaving them without control of Congress.
The dynamic leaves Mr Biden with little choice but to try to govern from the vanishing middle of a Washington that has been badly ruptured by the tumult of the last decade.
With the forces of partisanship and gridlock entrenched, ending what Mr Biden called the “grim era of demonisation” could be the central challenge of his presidency — and one that could prove vexing if forces on the left and right refuse to go along.
“There is a certain opportunity for bipartisanship, but it is all going to be deals in the middle,” said Rohit Kumar, a former aide to Senate Majority Leader Mitch McConnell, Republican.
“What I don’t know is whether the (Democratic and Republican) parties will allow them to do that because the parties have gotten a lot more polarised.”
While it is not settled, Mr Biden faces a high likelihood of becoming the first Democrat in modern history to assume office without his party controlling Congress.
Republicans are favoured to retain control of the Senate heading into two runoff elections in Georgia in January.
Democrats have already won the House.
Republican control of the Senate would force Mr Biden to curtail his ambitions, all but guaranteeing that big issues like climate change, immigration and expanding Obamacare remain mostly unaddressed.
But it would also create space for a different kind of legislative agenda — one founded on bipartisanship and consensus that would seem to play to Mr Biden’s strengths.
And some politicians say voters made clear in the election that governance from the middle is exactly what they want.
Among them is Senator Susan Collins, a Republican, who emerged from a brutal reelection campaign empowered to pursue a brand of pragmatic centrism that was once common among politicians but is now quite rare.
“I have seen, based on the number of phone calls that I have received from both the Democratic senators and Republican colleagues, a real interest in trying to expand the centre and work together to confront some of the challenges facing our nation,” Ms Collins said.
“And I’m encouraged by that.”
The glass half-full also depends on a sympathetic appraisal of Mitch McConnell, a much-loathed nemesis of Capitol Hill Democrats with a penchant for hardball tactics — and who is no stranger to obstructionism.
Mr McConnell is an old friend of Mr Biden’s, and as vice president, Mr Biden worked successfully with the Kentucky Republican to avert several tax- and budget-related crises during the Obama administration, including a tax increase on higher-income earners in exchange for renewing most of the 2001 Bush tax cuts.
Mr McConnell has not let much legislation hit the Senate floor recently, but has the muscle memory to do bipartisan deals when he sees them.
Often, these bills offer political benefits to his members, like a 2016 bill to fight the opioid menace or a widely backed public lands bill this year.
Other recent deals include Covid relief, a 2015 road bill and a 2016 cancer-fighting “moonshot” bill that was delivered as a goodwill gesture to Mr Biden, who lost his son Beau to brain cancer in 2015.
But the space for bipartisanship has contracted, with hardly any political middle remaining on Capitol Hill.
Soon there will no longer be any white southern Democrats in the House or Senate, while in the Republican party there are only a handful of moderates left.
Mr Biden, by contrast, served in a Senate where Democrats represented strongly Republican states in the South and the Great Plains, and where Republicans represented now-Democratic bastions like Minnesota and Oregon.
Compromise came more easily under such circumstances.
Now the party breakdown of the chamber is mostly determined by whether a state is red or blue on the presidential map, with Republicans dominating the South and Midwest and Democrats controlling the West Coast and most of New England and the Middle Atlantic.
Democrats are not giving up on the two Georgia runoff elections, given the stakes.
Control of the chamber would afford Mr Biden the opportunity to craft a Democrats-only budget bill that could reverse some of President Donald Trump’s tax cuts, expand the Affordable Care Act, and boost tax credits for the poor.
“The difference between a 50-50 Senate controlled by Democrats and a 51-49 Republican-controlled Senate could not be any more stark,” said veteran Democratic Senator Dick Durbin of Illinois.
But even if Democrats win both Georgia runoffs, the hopes of progressives for ramming through a liberal agenda by getting rid of the legislative filibuster, the 60-vote threshold for most legislation, are simply gone.
The Biden-McConnell relationship is crucial.