The Bernie Sanders campaign was built on big promises. There was the promise of affordable health care, the promise of free college, the promise of a higher minimum wage.
For voters who didn’t need, or want, those promises, he offered something else: That he alone could expand the electorate and win back voters who had turned away from the Democratic Party and embraced Donald J. Trump in 2016.
The coronavirus crisis turned everything that Mr. Sanders promised he was best equipped to do — fix the health care system, call out the dangers of a Trump presidency — into an agenda that was more urgent than ever for the country.
It was the moment for his message, but he was not the right messenger for the moment.
His promise was inherently risky, one that required, in his words, nothing less than a political revolution. And that is where the Sanders campaign fell short: In a world that had seemed risky enough already, revolution was just too much.
There were some signals that, despite the devotion of a broad coalition of supporters, the promises had always been too much.
Though he finished atop the field in Iowa, then won in New Hampshire and dominated in Nevada, Mr. Sanders was always unlikely to win states in the South, where former Vice President Joseph R. Biden Jr. had long shored up the support of black voters.
Before the coronavirus outbreak scrambled the rest of the calendar and pushed some races back for months, Mr. Biden trounced Mr. Sanders in the Midwestern battleground states — first Minnesota, then Michigan and Illinois — that were supposed to prove his case. Instead, Mr. Biden emerged as the candidate able to claim that he, not Mr. Sanders, could win over the voters that Democrats are counting on the most in November. Results for the Wisconsin primary on Tuesday are not expected to be known until next week, but Mr. Sanders was poised to lose there, too.
Mr. Sanders had expanded his base to include Latino voters, but he struggled with older voters. He struggled with suburban voters.
The promise he was able to fulfill was his promise to win over young people, an accomplishment that continued to be a particular point of pride even as his losses piled up.
“Not only are we winning the struggle ideologically, we are also winning it generationally,” Mr. Sanders said as he announced he was dropping out of the presidential race on Wednesday. “The future of this country is with our ideas.”
Mr. Sanders, who has referred to Mr. Biden as his “friend” and on Wednesday called him a “very decent man,” will need to continue to make a persuasive case to young people — especially on behalf of his former rival, who has had difficulty winning their support.
A Sanders rally was part concert, part sermon — a place for young and old to dance, somewhat perplexed, to a band called the Venomous Pinks opening for the impassioned stump speech about inequality; a traveling road show of constructive grievance that could dip in and out of three or four cities in three or four states in a day. Perhaps above all, it was a showcase for his promise of a country not led by the establishment, and most important, not by Mr. Trump.
Last spring, Mr. Sanders embarked on a five-state swing through the Midwest. It included stops in Wisconsin, Indiana, Michigan, Ohio and Pennsylvania. All were states that Mr. Trump won in 2016.
The tour was designed to demonstrate his sustained strength in those key battleground states. And he did, drawing the kinds of enthusiastic crowds and boisterous cheers that presaged his unexpected 2016 primary victories over Hillary Clinton in Michigan and Wisconsin.
He talked about the unfairness of trade agreements — some sentiments sounding similar to the president at times — but with the promise that he could actually do something about them.
He also vigorously attacked Mr. Trump.
“When we think about somebody setting an example for the children of this country, you don’t want somebody who lies all of the time,” he said at an April rally in Warren, Mich., near Detroit.
At another event in Warren, Ohio, he laced into corporations like General Motors, which had closed its Lordstown plant not far away. “We are sick and tired,” he said, “of you shutting down plants in this country and destroying families.” Voters in the crowd raised their fists and applauded thunderously.
He would return to the message again and again at rallies over the next year. “He lied,” he would say about Mr. Trump, dropping his voice into a minor key. “He lied.”
So what now?
Mr. Sanders has transformed the left: Policies like “Medicare for all” and eliminating student debt are not just accepted by many Democrats, they are embraced.
He has changed the way Democrats campaign: Candidates are now meant to be embarrassed by big-dollar donors.
He has inspired an enduring progressive movement: A legion of young politicians like Representative Alexandria Ocasio-Cortez of New York now exhaustively champion his message.
And he has exposed a class divide in the Democratic Party: His message appeals to those who know what it is like to struggle; it often confuses those who don’t.
At a town hall event in December in Burlington, Iowa, a woman stood to speak, about a health care system that was failing to help.
“Depending on what doctor you go to, they may not even believe that you have these things,” she said.
“So what do you do?” he asked brusquely.
“Cry,” she said. Her voice shook.
“OK,” he said.
His real promise — that life doesn’t need to be this hard — was for these people. On Wednesday, he vowed to continue fighting for his promises as he works to protect the “health and economic well-being of the working families of our country” during the coronavirus crisis.
But wrapped up in his speech was the concession that he did not need to be a presidential candidate to do so. Nor would he be.
“I wish I could give you better news,” he said, addressing his supporters officially for the last time. “But I think you know the truth.”