And the progressive organizations and operatives who rallied around his presidential campaign — "the Bernie Mafia," as they call themselves — feel as though they've finally won a seat at the adults' table in the Democratic Party while the Clinton machine retreats.
In the days since the presidential election, Sanders — who is an Independent and not officially a Democrat — has been promoted to the Democratic leadership in the Senate. One of his top allies, Rep. Keith Ellison of Minnesota, has become the front-runner to be the next chairman of the Democratic Party, which largely opposed him in the primary. And Sanders is already encountering "Bernie 2020" signs and T-shirts wherever he goes, while batting away reporters' questions about another presidential bid.
He's on a tour to promote his new book, and everyone seems to want his opinion on the election — especially since, during the primaries, he won many of the key Midwestern counties against Clinton lost in the general election.
His Facebook page grew by 100,000 followers in the 24 hours after Clinton's defeat.
No one associated with Sanders wanted Donald Trump to win, and many in his movement worked hard to boost Clinton. But Sanders and his allies can't help but feel some vindication. Mainly, though, they see an opportunity to assert themselves in the chaos of a decapitated Democratic Party.
Wednesday night in Washington, as Clinton delivered an emotional coda to her campaign on one side of town, Sanders was igniting a packed auditorium of college students with a tough-love vision for the future of the Democratic Party.
"I think a lot of people gave up on the Democratic Party in terms of standing up for working people and then said, 'OK, I'm going to go with this guy,'" Sanders said of Trump.
"Ordinary people have got to know that the Democratic Party has the guts to stand up to some very powerful people today whose greed is destroying the middle class and working class of this country," he said. "And if we can't do that, I don't see much of a future for the Democratic Party."
The next morning, at a breakfast with reporters hosted by The Christian Science Monitor, Sanders was the one reassuring Clinton of safe passage and a "very important role ... in the future of the Democratic Party."
Revolution Messaging, the digital firm that helped Sanders raise more than $200 million in small donations, sent an email to Democrats offering to help find jobs for laid-off Clinton staffers, who had expected to be waiting on calls from the Office of Presidential Personnel at this point.
Some Clinton allies and former staffers find the told-you-so subtext of Sanders' display off-putting, especially when he said last week that he thought he could have beat Trump. And they believe that he hurt Clinton by poisoning his millennial supporters' views of her.
The Bernie Mafia has tried to avoid gloating, but its mood has been transparently more upbeat than in the Clinton world.
Later Thursday, Sanders was speaking at what felt like a campaign rally organized by National Nurses United, a pro-Sanders union. The audience waved "Bernie 2020" signs that the union had printed, and he shared the stage with friends from this year's campaign, like former Ohio state Sen. Nina Turner and Larry Cohen, former president of the Communications Workers of America.
"I'm not here to blame anybody, not to criticize anybody, but facts are facts," Sanders said. "When you lose the White House to the least popular candidate in the history of America, when you lose the Senate, when you lose the House, and when two-thirds of governors in this country are Republicans, it is time for a new direction for the Democratic Party."
Sanders hardly got here alone. Appearing on the scene at the right moment, he gathered existing threads of progressive activism and bundled them for a common purpose, while also inspiring new groups and training new organizers. That network will continue to operate inside the progressive movement and the Democratic Party.
"This is the political revolution. It's here," said Winnie Wong, a prominent Occupy Wall Street activist who started the group People for Bernie. "What we know is that the Bernie Mafia feels confident and united."
As Sanders took his book tour on the road over the weekend, leftist organizers gathered in Washington for the annual RootsCamp conference. The 1,800 attendees had been expecting to plot ways to hold a Clinton administration accountable and push her to the left on key issues, but resisting Trump had become the new mission.
"This tragic loss is a dark, dark cloud that hangs over everything. But the small but important silver lining is that we can finally have the discussion and battle inside the Democratic Party that we've been needing to have," said Neil Sroka, communications director of Democracy for America, which backed Sanders.
RootsCamp offers both highly technical seminars on digital political organizing tactics and rooms set aside as "safe spaces" for art and physical movement. And while one attendee was told that any discussion of the election is "triggering," there were plenty of post-mortem opinions.
Joseph Geevarghese, director of the labor-backed advocacy group Good Jobs Nation, which has helped lead the push for a $15-an-hour minimum wage, said the issue was emblematic of how Democratic Party has muddled its economic message.
"Bernie said it directly. Hillary Clinton said $12 and a worker cooperative," Geevarghese said. "They've cast their lot with the WalMarts of the world, so is there any surprise that workers walked away? It's not just white workers. It's black workers, Latino workers. Workers walked away."
After last week, however, "there is the opportunity for a new beginning where the Democratic Party can return to its economic populist roots," Geevarghese said. "That is the only chance we have."
As progressives see it, the Democratic establishment made a mistake by overruling them and putting all their eggs in Clinton's basket.
"A 30-year drift toward neoliberalism in the Democratic Party establishment damaged the Clinton campaign in ways no message could fix," said Joe Dinkin, communications director of the Working Families Party. "That allowed Trump's phony populism to flank Clinton on jobs and trade."
Many progressives expect the party establishment to reassert itself and fear that it will re-establish itself as if nothing changed. But so far, they've met little resistance.