The first person Sanders went after was not Clinton but rather presumptive GOP nominee Donald Trump. "The American people in my view will never support a candidate whose major theme is bigotry," Sanders said, directly answering Trump's attempts to appeal to the Vermont senator's voters. "We will not allow Donald Trump to become president of the United States."
Then Sanders ticked off the main goals of his campaign: Combating inequality, taking on Wall Street, reforming the campaign finance system, guaranteeing universal health care and reforming the immigration system.
But Sanders then told the adoring crowd that these goals were not inextricably linked to his campaign alone. "But you all know it is more than Bernie. It is all of us together," he said. "It is what this movement is about. It is millions of people from coast to coast standing up and looking around them and knowing that we can do much, much better as a nation."
At that moment it sounded as though Sanders was about to concede. He didn't. But he did appear to be guiding the "Feel the Bern" airplane to a soft landing, one he might complete after Washington, D.C., completes the voting next Tuesday. Sanders appeared to suggest he would not even concede at that point, saying "then we take our fight for social, economic, racial and environmental justice to Philadelphia, Pennsylvania!"
But he said he would take the fight to Philadelphia, not necessarily his campaign. There is no question Sanders will fight for the most liberal platform possible and try and prevent Clinton from pivoting too hard to the center. He wants to influence the VP selection and get a prominent speaking slot.
He's likely at his maximum bargaining power now. Should Sanders choose to keep his campaign alive after the voting ends, he will begin to be marginalized by the rest of the party, including President Barack Obama, who congratulated Clinton on getting the delegates necessary to win the nomination and is close to issuing a full endorsement.
If Sanders refuses to concede after D.C. votes, he will go from powerful liberal titan to party pariah almost instantly. Sanders has little love for the party — he was an independent before the presidential race — but it's hard to imagine he wants to be remembered as a bitter dead-ender who made Clinton's race against Trump much harder by refusing to direct his supporters to the presumptive Democratic nominee in the critical weeks before the convention.
Sanders ended his address with a line reminiscent of then-Sen. Ted Kennedy's speech to the Democratic convention in 1980. Kennedy, who lost a strong primary challenge to incumbent President Jimmy Carter, exhorted his supporters saying "the work continues ... and the dream will never die."
Sanders chose "the struggle continues." But the struggle is not the campaign. And it can continue in ways that don't include denying the reality that Sanders has lost.
— Ben White is Politico's chief economic correspondent and a CNBC contributor. He also authors the daily tip sheet Politico Morning Money [politico.com/morningmoney]. Follow him on Twitter @morningmoneyben.