When David Hogg turned 18 on Thursday, he tweeted to his three-quarters of a million followers, “Now that I’m 18 I can vote will you?” Hogg and his classmates, student leaders in the #NeverAgain movement that grew out of the school massacre in Parkland, Fla., in February, have become national figures in their creative response to the killing of 14 students, a teacher, a coach and the athletic director at their high school. They’ve organized local and national demonstrations for gun control, confronted lawmakers, led other teenagers to register to vote, and inspired more than 1,000 school walkouts across the United States, with another national walkout scheduled for April 20, the 19th anniversary of the Columbine massacre.

Not bad, so far. But is it a social movement or a flash of youthful passion and grievance? Will it last and matter?

If so, it will involve far more than guns. Successful U.S. social movements are sustained collective efforts to promote change, uniting protest with mainstream politics. They are abiding, inclusive and opportunistic. They change and grow both when they win and when they lose. A movement can start with one issue, then build and reshape as it includes more people and embraces broader politics and culture. For the Parkland teenagers, this might mean, say, forging ties with incipient movements focused on protecting children from climate change, outdated textbooks or student debt.

Young people have been at the forefront of most major social movements in American life. They have brought earnest energy and commitment to political struggles that led to large-scale change: College students organized divestment campaigns to support reform in South Africa in the 1980s. Chicano high schoolers walked out of class to protest educational inequality in 1968. Even elementary school students have had their moment: In 1963, they engaged in a “children’s crusade” for civil rights in Birmingham, Ala., braving police dogs and fire hoses. Young people don’t know what’s not possible, so they can pursue causes with abandon. High school students who walked out in support of gun control last month, facing suspension or even paddling (in one report from rural Arkansas), demonstrated exactly this kind of commitment.

But student campaigns don’t win by themselves. Alliances are what lead to more activism — demonstrations, electoral campaigns, economic pressure. The divestment push, for example, spurred resolutions in Congress and civil disobedience at the South African Embassy in Washington, and when rock guitarist Steven Van Zandt took up the cause, a diverse collection of musicians organized to produce a powerful video musically announcing an artistic boycott of South Africa. All of this increased pressure on the apartheid government. The Parkland teenagers have attracted their own famous supporters, including Miley Cyrus, George Clooney and Oprah Winfrey — without allowing the celebrity spotlight to dim their issues or leadership.

The four college freshmen who staged a sit-in at a lunch counter in Greensboro, N.C., in 1960 are an instructive example of how a nascent campaign can snowball. They hopped onto a larger movement that had developed over the years through public meetings, court cases and a famous bus boycott, and they brought fresh urgency, a radical edge and a new organization — the Student Nonviolent Coordinating Committee (SNCC). Attention to the lunch-counter protests and their victories encouraged others. SNCC allied with other groups to stage the March on Washington in 1963 and then drew Northern students to Mississippi to register black voters. They sent an integrated delegation to the Democratic National Convention in 1964. Constantly demanding more, young organizers promoted the voting rights and civil rights bills. Although SNCC fell apart because of internal tensions over tactics and leadership, its influence went much further. Effective activism is contagious: Students who took their first steps with civil rights came to see a range of other social ills demanding their attention and applied what they’d learned in one campaign to the next one. SNCC veterans animated the free-speech, antiwar and feminist movements that followed.

Such linking of agendas is always risky — recall the pushback that Martin Luther King Jr. received for opposing the Vietnam War. But it’s necessary for a vital social movement. Those unable to innovate and adapt are sprinkled in the footnotes of American history: How much do most people know about once-significant campaigns for water fluoridation, welfare rights and world federalism? What in the 1960s came to be known as “the movement,” on the other hand, eventually included local campaigns and emerging feminist, gay rights and environmental causes, as well as the original civil rights and antiwar efforts. None of it was easy, but it allowed the movement to grow in changing circumstances.

In the same way, the Parkland students joined a political battle about guns already decades underway. Their experience as survivors — and their debate- and drama-class-drilled appeal — has helped them command national attention. Last month, they successfully pressured Florida to ban bump stocks and raise the purchase age for long guns to 21. These measures are extremely modest but nonetheless represent significant change in Florida, one of the most gun-friendly states, where almost any adult can legally carry a concealed weapon almost anywhere.

The students were clear that they wanted more, even if progress and commitment have come at a price. The young activists have faced increasingly vicious attacks from online trolls, conservative politicians, and radio and television hosts. But they have mostly demonstrated the resilience they’ll need to continue. Hogg, for example, cleverly turned Fox host Laura Ingraham’s barbs about his grades and failure to gain admittance to several colleges into a challenge to her advertisers; more than a dozen quickly decided to drop her show. (Hogg has just been accepted to the University of California at Irvine, where I teach a course on how social movements in America emerge; I had nothing to do with his application, but I hope he enrolls here and takes the course.)

The teenagers are attentive and opportunistic. This past week, for example, Parkland survivors flooded Twitter as soon as House Speaker Paul Ryan announced his intent to retire, demanding that he allow a vote on modest gun-control measures. At the same time they are ready to escalate. Another Parkland student, Emma González, has emphasized that the campaign against gun violence is intrinsic to her concerns about gay rights. Her classmates, recognizing that their relative advantages (the student leaders are mostly white) and affluence have helped them win national attention, have deliberately shared their spotlight with people who don’t have those attributes. Edna Chavez, a Latina student from South Los Angeles, and Zion Kelly, a black student from Washington, both spoke at the Parkland-organized March for Our Lives rally on the Mall last month, moving the crowd as they described the loss of their brothers to gun violence. Expanding from Florida to include Los Angeles and Washington, as well as Chicago and Sacramento, the Parkland teenagers explicitly called upon children to fight gun violence carried out not only by crazies and criminals but also by the police.

A broader and more comprehensive agenda risks provoking new opponents, but it also affords the chance to reach additional supporters and builds a movement’s capacity to survive ebbs in attention and respond to new events and opportunities. Jaclyn Corin, another Parkland teen leader, stood beside MLK’s 9-year-old granddaughter, Yolanda Renee King, at the Washington march, and Yolanda appeared with Corin at an Atlanta event two weeks later commemorating the civil rights leader.

Today’s young activists may find themselves enmeshed in something larger, smarter, more diverse and ultimately more powerful than movements of the past. A recent Washington Post-Kaiser Family Foundation poll found that 1 in 5 Americans had participated in a protest or political rally since the beginning of 2016 — and almost 20 percent of them said they had never before taken part in a march or rally. The Women’s March after President Trump’s inauguration, probably larger than any demonstration in American history, was followed by more-focused campaigns on behalf of immigrant rights, science, tax justice and the environment. So far, these actions and others are linked only by antipathy to the Trump presidency. But there are hints of a broader agenda that could unite them: It would focus on protecting and supporting America’s children.

Entrepreneurial activists determined to protect young people could make common cause with the teachers in West Virginia, Oklahoma and elsewhere who have walked out of school in droves to demand better salaries for themselves and fresh textbooks for their students. The teachers win when they convince parents that tax cuts in their states came at the cost of their children’s futures. Young activists can recognize slightly older allies pressing their colleges to divest their holdings in fossil fuels to protect the planet. As the students look for help, they will also find shared interests with older brothers and sisters struggling to afford college and manage student debt, defining personal struggles as national problems. The vision that links these causes comes from looking relentlessly ahead, rather than back to an imagined “great” past. The students who marched for gun control last month are likely to keep marching — and not just about guns; the question is who will be with them.

Twitter: @davidsmeyer1

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