Recent elections are bringing the largest crop ofself-described socialist candidates in nearly a century, not just in New York and on the Left Coast, but in places like Virginia and Pennsylvania. For critics, this represents a futile and dangerous radicalism; for some who welcome it, it’s nothing more than a youthful resurgence of Ted Kennedy-style liberalism.

The reality is more interesting. The new socialism is both thoroughly American and pretty damned radical. Much of today’s “socialism,” like Bernie Sanders’ presidential campaign, has deep roots; it’s basically the left wing of New Deal and Great Society liberalism, promising free higher education and universal health care, stronger unions and more support for affordable housing. These were once the bread and butter of the Democratic Party. But the new socialism is also genuinely radical—and not just because the country has moved so far away from the goals of widely shared wealth and leisure of Lyndon B. Johnson’s Great Society.

Even saying “socialism” opens up questions that mainstream politics and policy had set aside. What would it mean to make the economy genuinely supportive of personal dignity and equality? Should more of our business infrastructure be treated like public utilities rather than profit-maximizing companies? Should policy encourage cooperative, worker-owned enterprises? Should the goal of labor law be universal unionization in large businesses, to counteract the inevitable power of owners and managers? Even posing the questions, under the banner of a term that was anathema just a decade ago, moves the horizon of political possibility. ...