The labor movement demands constant, often thankless struggle, but its fortunes are cyclical. The history of the movement is a history of unceasing endurance rewarded by moments of sudden extraordinary transformation, followed by long, bitter retreats. Such moments happened in the 1830s, in the 1870s and the 1880s, before World War I, in the 1930s, and in the late 1960s and early 1970s. Each episode was marked by the efflorescence of new organizations, the development of new tactics, the participation of new workers in new industries—and then, eventually, defeat. As Eugene Debs observed of this pattern in 1904:

Ten thousand times has the labor movement stumbled and fallen and bruised itself, and risen again; been seized by the throat and choked and clubbed into insensibility; enjoined by courts, assaulted by thugs, charged by the militia, shot down by regulars, traduced by the press, frowned upon by public opinion, deceived by politicians, threatened by priests, repudiated by renegades, preyed upon by grafters, infested by spies, deserted by cowards, betrayed by traitors, bled by leeches, and sold out by leaders, but, notwithstanding all this, and all these, it is today the most vital and potential power this planet has ever known.

It’s been clear since the early 1980s that we’re going through a rough period, but, as Debs recalls for us, the cyclical pattern of working-class history offers a source of comfort. The long view allows organizers to remind one another that down does not mean out—that we’ve been here before and come back from it, and not just once but many times. I can’t begin to count the number of times I’ve raised my hand in a union meeting and relayed the experience of union militants in the 1920s, who saw their comrades arrested and fired, witnessed their organizations smashed and destroyed, and watched their workmates turn against them. How useful a reminder: That was the last period when union density was as low as now, or when inequality was as great. If militants in the 1920s had not persisted, even as they were marked as pariahs in their shops, the heroic 1930s would never have come about.

And yet, while it has seemed like a good axiom that this dynamic is internal to the pattern of capitalist economic development, and will live as long as capitalism does, no historical cycle lasts forever. Moreover, our own period of defeat is now much longer and arguably more profound than any of its prequels. At some point, confidence based in historical memory starts to turn into a kind of quasi-mystical faith. It’s one thing to believe that history has a pulse-like pattern; it’s another to cling to a corpse after it has given up the ghost.

Now, with Janus v. American Federation State, County, and Municipal Employees, the Supreme Court may have pushed this tension to its historical breaking point. In a decision that has proved even worse than expected, the Court has finally dealt public-sector unions the crippling blow that conservative groups have long been pushing, and that labor activists have long feared: It has determined that public employees are no longer required to pay any fees for union representation, and, in the process, has likely deprived unions of many thousands of members and millions of dollars. Moreover, the Court didn’t stop there. Its decision also raises the bar for union membership by turning it, for the first time, into something workers must opt into, rather than giving them the choice to opt out. And, in his majority opinion, Justice Samuel Alito further invites a challenge to the very concept of exclusive representation by a single union in a given workplace—the bedrock of American labor law. This appears to be an offer to overrule the 1935 Wagner Act.

With so many anti-labor land mines planted in a single decision, it’s tempting to write the labor movement’s obituary—and a few years ago, something like Janus would almost certainly have seemed lethal. When unemployment was high, workers had little confidence, and workplace ferment was at a historically low ebb, a “right-to-work” ruling would almost certainly have meant further demoralization and disorganization. It was not hard to imagine the ensuing death spiral.

Some of that will surely happen now too. Public-sector unions will bleed membership and resources; their capacity for external activities such as election campaigning will shrink too, weakening progressive politicians. Yet there’s also reason to think that the fallout from the decision may be a more ambiguous affair, that it could even serve as the kind of rejuvenating shock the movement needs—the kind that heralded previous moments of rapid growth.

First, public-employee unions, already under assault at the state level, have shown that they are able to keep their members engaged to a surprising degree in recent years. Iowa, for example, has taken to requiring public-employee unions to seek recertification regularly, only to find that workers have overwhelmingly voted to recertify. Similar stories are now beginning to appear all over the country: Locals that have long seemed moribund are finding that workers are more willing to join, engage, and fight than they have been in recent memory.

In his opinion, Alito doubted whether the fair-share fee is important any longer to labor peace—one of its original justifications. Wrote Alito, “Whatever may have been the case 41 years ago when Abood [the 1977 Supreme Court case that established the fair-share paradigm] was handed down, it is now undeniable that ‘labor peace’ can readily be achieved ‘through means significantly less restrictive of associational freedoms’ than the assessment of agency fees.” This is the opinion of a conservative who has never seen a fighting working class and does not believe such a thing is really possible any longer.

In fact, Janus arrives in the midst of something of a strike wave. Touched off by the West Virginia teachers in February and spreading rapidly among public-education workers in multiple states, this series of actions has also seen dramatic mobilizations in the University of California medical centers and among graduate teachers and researchers on multiple campuses. Last month, 25,000 Las Vegas casino workers gathered in a stadium to vote to strike, after which employer resistance rapidly crumbled—and in a “right-to-work” state, no less. Most recently, Teamsters working for UPS have authorized a strike; theirs is one of the largest collective-bargaining agreements in the United States, covering 280,000 workers. The potency of the strike threat appears to have broken the employer’s resistance and brought about a tentative agreement from UPS. And like the casino workers and UC system employees, as well as graduate workers at Columbia University and the New School in New York City, the Teamsters voted over 90 percent for the strike authorization.

This rising tide of militancy has been brought on by the improbable confluence of labor’s dire straits, the execrable national political situation, low unemployment, and stagnant wages. In this environment, workers are finding themselves more eager for a fight than they have been in recent memory.

Labor’s recovery will not be easy. It will ultimately depend on both militant shop-floor confrontation and large-scale political and legal change—progress in each sphere reinforcing progress in the other. The movement’s ranks and resources are still likely to be depleted by Janus, making such an offensive logistically harder to conceive. Many public-sector unions have no internal organizing program to achieve this.

But the surviving rump of the labor movement now looks likely to be more militant and mobilized than we might have imagined just a few years ago. A militant minority in the American workforce, isolated but unafraid, brings us substantively nearer to the case of the 1920s than we have been for some time—in addition to the superficial similarities that have existed for years now. The institutional conservatism created by a residual dues-paying passive membership will no longer restrain the ambitions of those who persist in the movement. Such a situation is no guarantee of recovery. Now that workers have shown they want to fight, however, it becomes possible—necessary—to begin to plot the path back.