...It’s too simple to say that Marxism is back, because it never truly went away. In the United States after the fall of the Berlin Wall, though, it was largely confined to university English departments, becoming the stuff of abstruse, inward-looking and jargon-choked cultural critique. Then came the economic crash, Occupy Wall Street, and the ongoing disaster of austerity in Europe. “Around the time of Occupy in particular, a lot of different kinds of lefties, working at mainstream or literary publications, sort of found each other, started talking to each other, and found out who was most interested in class politics,” says Sarah Leonard, the 25-year-old associate editor of Dissent, the social-democratic journal founded almost 60 years ago by Irving Howe. “We have essentially found an old politics that makes sense now.”

In the United States, of course, Marxism remains an intellectual current rather than a mass movement. Certainly, millennials are famously progressive; a much-discussed 2011 Pew poll found that 49 percent of people between 18 and 29 had a favorable view of socialism, while only 46 percent felt positively about capitalism. It’s hard to say exactly what this means—it’s not as if young people are sending Das Kapital racing up the best-seller lists or reconstituting communist cells. Still, it’s been decades since so many young thinkers have been so engaged in imagining a social order not governed by the imperatives of the market.

The reason why is obvious enough. “Now everything is falling apart,” says Doug Henwood, publisher of the Left Business Observer and mentor to several among the new Marxist thinkers. “Not even the most energetic apologists can say things are going well. The basic premises of American life, about upward mobility and all that, it all seems like a cruel joke now.”...