On the last Tuesday in June, six-term Mississippi Senator Thad Cochran narrowly won a hard-fought Republican run-off election against his virulently anti-government Tea Party challenger, Chris McDaniel. The reason, the pundits quickly concluded, was an unprecedented surge in black Democrats—some 13,000 or more—crossing over to support Cochran. “It should send a message,” said retired school principal Ned Tolliver. “It shows that we have the power to elect who we want to elect when the time is right.”

Around the time the polls closed, a very different view of Mississippi was playing out on PBS, in the form of the documentary Freedom Summer. A gripping account of the 1964 movement that brought hundreds of college students to register black voters, the film is part of a flood of fiftieth-anniversary commemorations of that epic struggle. In grainy black-and-white footage and interviews with the heroic Americans who risked beatings, firebombings and even death, the film reminds us of the long struggle of African-Americans for the vote and celebrates those who made it possible.

There’s much to celebrate. Mississippi, where only 28,000 blacks were registered to vote in 1963, now boasts more black elected officials than any other state—including the recently re-elected mayor of Philadelphia, scene of the brutal 1964 murder of civil rights workers Andrew Goodman, Michael Schwerner and James Chaney.

The White and Colored signs have long since come down, and a black man now sits in the Oval Office. But fifty years after Freedom Summer, America faces the greatest assault on voting rights since the Jim Crow era, with the Supreme Court eviscerating the Voting Rights Act last year and twenty-two states passing new voting restrictions since 2010. Poll taxes and literacy tests have been replaced with burdensome new laws that keep 3.7 million eligible black voters unregistered across the South. And an estimated 2.6 million ex-felons—including nearly 8 percent of all black adults—are barred from voting, despite having served their sentences.

As more and more Americans lose what Lyndon Johnson called “the basic right without which all others are meaningless,” Republicans are trying to take the country back to a past we’d rather not revisit. In North Carolina, a particularly egregious example, the GOP-controlled state government has slashed unemployment benefits, blocked expansion of the minimum wage, opted out of the Affordable Care Act’s Medicaid expansion, cut universal pre-K, cleared the way for fracking, enacted one of the nation’s harshest voter-ID laws, and dramatically reduced access to abortion while allowing concealed weapons in bars, schools and playgrounds.

All of this reinforces why, as Martin Luther King III says, we need “not just this moment of reflection, but also a year of action.” Activists and advocates are taking that charge seriously. Senator Patrick Leahy and Representatives John Conyers and James Sensenbrenner are leading a push to restore the overturned section of the Voting Rights Act. Representatives Keith Ellison and Mark Pocan have proposed a constitutional amendment to guarantee the right to vote for all Americans of legal age. Even GOP Senator Rand Paul—an opponent of the 1964 Civil Rights Act—has introduced a bill to restore federal voting rights to nonviolent felons.

Meanwhile, fired by the same spirit that drove their predecessors, young people, minorities and progressives are, in the words of civil rights legend Bob Moses, stepping up to “earn their insurgencies.” The Moral Monday protests in North Carolina will be joined this summer by the activist network Freedom Side—#FreedomSide for the Twitterati—which plans to train 4,000 volunteers and register 30,000 voters across the country. They’re fighting on a broad spectrum of issues, from voting rights to mass incarceration to immigration reform to youth unemployment. “The best way to commemorate Freedom Summer is to reinvent it,” the group says, “and take back the democratic process for our generation.”

Indeed, freedom takes more than a summer. It’s time for all of us to earn our insurgencies.