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 let me tell you this: He’s already succeeded beyond anyone’s imagining.

I remember when he launched his campaign in April 2015. The media labeled him a “fringe” candidate. Comedians made fun of his hair and his frumpled look.

Political junkies smirked. How could a 74-year-old, political Independent, Jewish, 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 - he 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.

He has helped shape the next generation.

Even more remarkably, he did it without Superpacs or big money from corporations, Wall Street and billionaires. He did it with small contributions from millions of us.

He’s shown it’s possible to come within a stone’s throw of getting the Democratic nomination for president of the United States (granted, it’s not really over until superdelegates vote July 25), without selling your soul or compromising your conviction.

That’s a big deal. It gives lie to the often-repeated claim by Democratic 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.

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 that happens, nothing else that’s important for America to do can be done. It’s not possible 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 healthcare costs under control when big pharmaceutical companies and giant insurance companies have so much influence in Washington.

Sanders has forced a serious debate about many of the initiatives he has proposed, such as the necessity of single-payer healthcare, free tuition at public universities, a $15 minimum wage, busting up the biggest Wall Street banks, taxing the 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. I predict many will ultimately be enacted.

Just as progressive leaders at the turn of the last century – “fighting” Bob LaFollette, William Jennings Bryan, and Hiram Johnson – laid the foundation for Teddy Roosevelt’s era of progressivism, Sanders has laid the foundation for a new progressivism. And because America now finds itself burdened as it was then with wide inequalities of income, wealth, and political power, his leadership has been essential.

Sanders’ courage in taking on the political establishment has emboldened millions to stand up and demand our voices be heard.

Regardless of what Sanders decides to do now, he has ignited a movement that will fight onward. We will fight to put more progressives into the House and Senate. We will fight at the state level. We will organize for the 2020 presidential election. We will not succumb to cynicism. We are in it for the long haul. We will never give up.