I don't know what Bernie Sanders is going to do from here on, and I'm not going to presume to advise him on his next steps. He's earned the right to figure out for himself what's next for his campaign and the movement he has launched.
But of this I'm sure: He has already succeeded beyond anyone's imagining.
I remember when Sanders launched his campaign in April 2015. The media labeled him a "fringe" candidate. Comedians made fun of his hair and his rumpled look.
Political junkies smirked. How could a 70-something, Jewish, politically independent self-described democratic socialist take on the most powerful political machine in modern history? How dare he rail against the establishment, the mainstream media and the moneyed interests? They said he had a "zero chance" of getting anywhere.
Then he won 22 states.
And in almost every state — even in those he lost — Sanders won vast majorities of voters under 30, including a majority of young women and Latinos. By March he had accumulated more votes among voters under 30 than had Hillary Clinton and Donald Trump combined. He also received the most votes from people under 45.
Sanders has helped shape the next generation.
Even more remarkably, he did it without super PACs or big money from corporations, Wall Street and billionaires. He did it with small contributions from millions of average Americans.
He's shown it's possible to come within a stone's throw of getting the Democratic nomination for president of the United States without selling your soul or compromising your conviction.
That's a big deal. It gives lie to the often-repeated claim by candidates that, while they believe in reforming America's campaign finance laws, they won't run "with one hand tied behind their back" and therefore must rely on big money in order to compete effectively.
Sanders has shown that with a powerful message delivered by a messenger with passion and conviction, small donations will pour in.
He's also inspired millions to get involved in politics — and to fight the most important and basic of all fights on which all else depends: to reclaim our economy and democracy from the moneyed interests. Unless and until our democracy is reclaimed, nothing else that's important for America to do can be accomplished.
It's difficult to reverse climate change when big energy companies dominate politics. It's hard to achieve equal opportunity when big corporations and Wall Street pay for special privileges and corporate welfare.
We can't have a sane foreign policy when military contractors hold sway. There's no way the nation can get health care costs under control when big pharmaceutical companies and giant insurance companies have so much influence in Washington.
It's impossible to enlarge the typical worker's paycheck when more and more of it goes to pharmaceutical companies, internet service providers, banks, food processors, airline carriers and health insurers — all of which raise prices because they have the market and political power to do so.
Sanders helped America see the vicious link between big money, political influence and the rigging of the American economy.
And he put before the public bold proposals that would not otherwise receive the attention they deserve: single-payer health care, free tuition at public universities, a $15 minimum wage, busting up the biggest Wall Street banks, taxing financial speculation, expanding Social Security, imposing a tax on carbon, and getting big money out of politics.
These proposals will shape the progressive agenda for years to come. Many will ultimately be enacted.
Just as progressive leaders at the turn of the last century — the "prairie populist" presidential candidate William Jennings Bryan,Wisconsin's "fighting" Bob La Follette, and California's Hiram Johnson — laid the foundation for Teddy Roosevelt's era of progressivism, Sanders has laid the foundation for a new progressivism.
That new progressivism is as relevant to today as was the older progressivism a century ago, when America was similarly burdened with wide inequalities of income, wealth and political power that threatened our economy and democracy.
Finally, Sanders' courage in taking on the political establishment has emboldened millions to stand up and demand that our voices be heard.
He has ignited a movement that will fight onward. It will fight to put more progressives into the House and Senate. It will fight at the state level. It will organize for the 2020 presidential election.
The millions who supported Bernie will not succumb to cynicism. They are in it for the long haul. They will never give up.
Former U.S. Secretary of Labor Robert Reich is Chancellor's Professor of Public Policy at the University of California at Berkeley and Senior Fellow at the Blum Center for Developing Economies. His new book, "Saving Capitalism: For the Many, Not the Few," is now in bookstores. His film "Inequality for All" is now available on iTunes and Amazon streaming.