Now that Hillary Clinton has reached the magic number of delegates to secure the Democratic nomination for president, the question on the minds of many Senate Democrats is, when is Bernie Sanders going to call it quits?
Sanders has repeatedly declared that he intends to remain in the race through the Democratic National Convention in July. He is meeting with President Obama on Thursday to discuss "significant issues at stake in this election," according to the White House. The president called the candidate Tuesday night to thank him for running an energizing campaign (meanwhile, he called Hillary Clinton to congratulate her on clinching the Democratic nomination).
And over in the Senate, it's getting awkward. In a chamber where members go out of their way to avoid directly chastising each other, the low-simmering annoyance with Sanders for staying in the contest is palpable.
"I think he should stand down now. That's my conclusion," said Democrat Bill Nelson of Florida. "I believe he is uniquely positioned to be able to be a unifier."
As Trump's rhetoric heats up against Clinton, many Democrats don't want her distracted by ongoing feuding with the Sanders campaign. And some of Sanders' Senate colleagues are taking note of each day he insists on competing instead of unifying. If President Obama endorses Clinton — as he's expected to as soon as this week — and Sanders refuses to concede, Nelson says it'll be a miscalculation.
"That's another reason that Bernie will have — from a pretty big guy saying, 'You ought to stand down. Become a unifier now,' " said Nelson.
How Sanders handles the coming weeks, or months, could directly impact the goodwill — and, therefore, clout — he'll enjoy in the chamber should he return. At the moment, Democratic leaders are gingerly giving the senator space to figure out his next steps.
"Bernie Sanders is going to make decisions on his own," said Minority Leader Harry Reid. "If he calls me and asks me for advice, I'll give it. In the meantime, I'm not giving any advice to the Sanders folks."
But other Senate Democrats say the way the Sanders campaign is defiantly carrying on could jeopardize the senator's influence if he tries to reshape his role in the Senate when he rejoins them.
"It all depends on what he does now," said Democrat Dianne Feinstein of California. "It all depends if he is willing to be a team player and willing to come together, and help the party move on and not create a problem."
Feinstein said what especially concerned her was the Sanders campaign's plan to try to flip superdelegates at the July convention. She called the effort "divisive in and of itself."
"I don't think he'll be successful. I think it's a useless effort," Feinstein said. "And I think in the time it's going to take to do that, what we need to do is put the two candidates together and have them march on to a general election together."
And in the months to come, Sanders' colleagues will be watching how generously he shares his massive email list to raise money for other Democrats. His fundraising network has broken records for small contributions for presidential candidates. Jon Tester of Montana, who chairs the Democratic Senatorial Campaign Committee, says he's not worried.
"Bernie's always been very good about helping us when we've asked," Tester said.
But he added that Sanders needs to jump out of the race before the July convention.
"I know Bernie, and Bernie's going to do the right thing, and when the time is right for Bernie, Bernie is going to get on board," Tester said. "How he handles the endorsement of Hillary and moving forward, getting on board — that's going to make a difference to some."
Despite the hard-charging tone of his campaign, Sanders has given some colleagues the impression that he wants very much to be in their good graces.
"He called me a few weeks ago — out of the blue," said Dick Durbin of Illinois, the second-highest-ranking Democrat in the Senate. "My impression was that he reached out because he believes that someday he'll be coming home to the Senate. And I think he wants to be part of the Senate and its future."
Durbin said Sanders could play a tremendously influential role in helping shape the party's agenda. He ticked off all the policy priorities where Sanders and the Democratic leadership overlap — income inequality, college affordability, Wall Street reform, climate change.
"I think Bernie's agenda is very close to our party's agenda, and I think we should be working with him," said Durbin.
But Durbin added that the size of Sanders' role will depend largely on how he handles the winding down of his campaign.
"Let me tell you — that is a critical element," said Durbin.