In late October 2011, I was volunteering at the Occupy Wall Street library in lower Manhattan. Tucked into a corner of Zuccotti Park, the library was staffed mainly by anarchists of an exceedingly orderly bent. If society were suddenly freed from coercive institutions like libraries, these people would gladly spend the morning sorting donated books by Dewey decimal number—as they were doing in the mild fall weather. I was there for only a few days, but one conversation with a book borrower has stayed with me. He was having trouble understanding why he kept returning to the encampment. He wondered: Had anything like this happened before? Were there books that could tell him who had done it, and why? I felt I was meeting a victim of a political shipwreck. In my mind, he became emblematic of a left that felt itself so unmoored from any shared past that it was puzzled by its own existence.

Now that Donald Trump occupies the White House, it’s easy to feel that we are all castaways in historical time. There is talk in some quarters of leaving the country, of turning blue cities and states into sanctuaries, not just for the undocumented, but for disillusioned liberals—a response that amounts to giving up on creating a just and inclusive democracy in this divided land. But such feelings of despair miss the deeper and perhaps more lasting political transformation that has taken place in the five years since Zuccotti Park.

Indeed, the irruption of radicalism at Occupy turned out to be prophetic. For the first time in decades, the left regained its focus and put down new roots. Fight for $15, the campaign for a higher minimum wage led by fast-food workers, made gains in New York, Los Angeles, Seattle, and San Francisco. Rolling Jubilee, founded in 2012, bought and canceled almost $32 million in medical and student debt. Black Lives Matter has forced America to reckon with police violence against black men and highlighted the economic isolation of many black communities. Last year, Bernie Sanders won more than 13 million votes. And recent polls show that a majority of Americans under the age of 30 now prefer socialism to capitalism. While it is unclear just what they mean by that, a renewed openness to radical ideas is unmistakable among young people. The mass protests in response to Trump’s policies, both at the women’s march and at airports around the country, in the last weeks show a sense of urgency and willingness to fight for robust legal equality and inclusiveness. At the very moment when establishment politics have been severely undermined—the GOP hijacked by Trump, the Democrats confounded by Hillary Clinton’s loss—the American left has been reborn.