Not long ago, a collective of young people issued a manifesto. They began by reflecting on the complacency of their childhood, and on their newfound spirit of protest. The “struggle against racial bigotry,” they wrote, has “compelled most of us from silence to activism.” Their generation, the authors proclaimed, was the last chance to convince the American public that there were alternatives to the debased present, and that something approaching a true democracy might actually be possible.

The manifesto in question comes from 1962: the Port Huron Statement, one of the central documents of the American New Left. It could, though, have come from almost any moment in the past century. The belief in the regenerative qualities of the youth is a warmed-over version of the old belief in inevitable historical progress. Since 1920, at the latest, every generation has had its champions—those who fervently believed that this would, at last, be the group of young people who would bring a chaotic world to order.

Although Millennials like me might prefer to forget it, we were once the chosen ones. I certainly remember popping Nirvana into my Discman and feeling certain that, once kids my age were old enough to wield real influence, the stuffed shirts wouldn’t know what hit them. As late as 2000, a spate of commentators thought that we would emerge as “the next great generation,” righting the ship of state after the tumult of the 1990s. Given our manifest failure, and our own stuffed shirts, another wave of pundits has foisted similar hopes on to Generation Z. In his first public remarks after leaving the presidency, Barack Obama declared that his daughters’ generation had an enlightened outlook, and that the biggest task in our politics was “to get this next generation and to accelerate their move towards leadership.” For Obama, the youth represent toleration and an opportunity to overcome polarization. For more left-leaning thinkers, they represent, instead, a well of pent-up revolutionary energy. The Justice Democrats announce in huge letters on their website that it is time to “elect the next generation.” And at Jacobin, Connor Kilpatrick and Matt Karp have argued that Bernie Sanders’s exceptional polling among young voters portends a rising tide of socialism.

There is good reason to be skeptical. Youthful energy can ricochet in all kinds of directions (Alexandria Ocasio-Cortez is young, but so is Madison Cawthorn). Previous hopes for a messianic wave of youth revolution have been dashed. Insofar as young people have exercised political agency, it has not necessarily been the sort that the left might like. After World War I, fascists capitalized on youthful enthusiasm better than their competitors, and in some European Union countries today, disgruntled youth are increasingly opting for the far right. Meanwhile, the vaunted history of social democracy is not really a story about youth. The postwar welfare regimes in both Europe and the United States, which so often enthrall contemporary observers, were built by older, battle-scarred men.