While Hillary Clinton secured the delegates she needed Monday to become the presumptive presidential nominee, Sanders channeled the defiance of his supporters as he took the stage shortly before 11 p.m. PT.
The crowd was on edge -- angry with the press and worried that he would give in to the growing pressure from Democratic leaders to bow out of the race.
But it wasn't long before it became clear from his remarks that his "movement" -- a campaign that has given Clinton more of a fight than anyone predicted and forced the Democratic Party to the left -- would carry on, at least through the final primary next Tuesday in Washington, D.C.
"All of you know that when we began this campaign over a year ago we were considered to be a fringe campaign. Over the last year I think that has changed a little bit," he said as the crowd thundered with approval.
"Let me thank you all for being part of a political revolution," Sanders said. "We understand our mission is more than just beating Donald Trump, it is transforming our country."
The Vermont senator said he had spoken to President Barack Obama and to Clinton, though the crowd booed when he said he had offered her his congratulations on her victories Tuesday night.
He noted his victories in North Dakota and Montana, and said he believed the gap between him and Clinton in California would narrow as results continued to trickle in.
"Next Tuesday we continue the fight," he said. "We are going to fight hard to win the primary in Washington, D.C., and then we take our fight for social, economic, racial and environmental justice to Philadelphia."
"The struggle continues," he added.
Though some Clinton supporters have pushed for Sanders to drop out for the sake of party unity, at least high profile Democrat was urging patience Wednesday morning. Vice President Joe Biden, in comments to CNN, urged Democrats to be "a little graceful
" and to give him time to make his decision.
Some election night parties take on subdued and funeral tone when the numbers have not settled in the candidate's favor, but that was not the case here among the legions of "Bernie or Bust" supporters who flocked to his final California rally.
Some carried signs urging him to mount an independent run; many said they would write him in this fall if Clinton becomes the nominee. Clinton had already claimed victory in New York when Sanders supporters began filling a cavernous airplane hangar in Santa Monica airport, but few said they had listened to her speech.
Many were seething with anger at what they viewed as the news networks' premature call for Clinton.
Before Sanders arrived a huge video screen towering above the crowd showed California's early returns—with Sanders losing by a large margin—the crowd shouted "Bulls---t! Bullsh---t."
When the channel flipped to CNN -- again showing the evening's strong results for Clinton -- the crowd thundered: "Turn it off! Turn it off!"
Many brushed off the notion that it was a historic night for Clinton, with some arguing that she had sold out to "the system" and could not be trusted as the Democratic nominee
When Clinton talks about breaking the highest, hardest glass ceiling, said Jennifer Hernandez: "I don't think she's broken anything."
"She's clearly bought and stolen her way to the top --- and she's been with the establishment for a really long time. She's been their nominee from the beginning, which was very unfair for Bernie," Hernandez said.
This fall if Clinton is the nominee, Hernandez said, she will write in Sanders on her ballot or vote for the Green Party's Jill Stein.
Melissa Baldridge, a 39-year-old digital marketing recruiter, said she was angered by what she saw as a rush to anoint Clinton.
"Everybody in the mainstream media is in such a rush to have the story first that they call things prematurely," said Baldridge, who said she switched her registration from Republican to Democrat to vote for Sanders.
She noted that superdelegates do not officially vote until the Democratic Convention next month, and insisted that they should not be counted until then. "By announcing that she had (the nomination), a lot of people decided to stay home. That's a form of voter repression."
Like many Sanders supporters, Baldridge said the hundreds of superdelegates who backed Clinton early in the process have a duty to reconsider their decision.
"If they are saying that they are for the people; that they are going to reflect the sentiments and the feelings of the people -- how can announce their allegiance so early on? It just feels like there's really no true democracy in this process," Baldridge said. "I hope with what Bernie is doing, we're changing, we're influencing and we're making things a lot more progressive."