Capital used to sell us visions of tomorrow. At the 1939 World's Fair in New York, corporations showcased new technologies: nylon, air conditioning, fluorescent lamps, the ever-impressive View-Master. But more than just products, an ideal of middle-class leisure and abundance was offered to those weary from economic depression and the prospect of European war.

The Futurama ride even took attendees through miniature versions of transformed landscapes, depicting new highways and development projects: the world of the future. It was a visceral attempt to renew faith in capitalism.

In the wake of the second world war, some of this vision became a reality. Capitalism thrived and, though uneven, progress was made by American workers. With pressure from below, the state was wielded by reformers, not smashed, and class compromise, not just class struggle, fostered economic growth and shared prosperity previously unimaginable.

Exploitation and oppression didn't go away, but the system seemed not only powerful and dynamic, but reconcilable with democratic ideals. The progress, however, was fleeting. Social democracy faced the structural crisis in the 1970s that Michal Kalecki, author of The Political Aspects of Full Employment, predicted decades earlier. High employment rates and welfare state protections didn't buy off workers, it encouraged militant wage demands. Capitalists kept up when times were good, but with stagflation – the intersection of poor growth and rising inflation – and the Opec embargo, a crisis of profitability ensued.

An emergent neoliberalism did curb inflation and restore profits, but only through a vicious offensive against the working class. There were pitched battles waged in defense of the welfare state, but our era has largely been one of deradicalization and political acquiescence. Since then, real wages have stagnated, debt soared, and the prospects for a new generation, still wedded to a vision of the old social-democratic compact, are bleak.

The 1990s technological boom brought about talk of a light and adaptive "new economy", something to replace the old Fordist workplace. But it was a far cry from the future promised at the 1939 World's Fair.

The 2008 recession shattered those dreams, anyway. Capital, free of threats from below, grew decadent, wild, and speculative.

For many in my generation, the ideological underpinnings of capitalism have been undermined. That a higher percentage of Americans between the ages of 18 and 30 have a more favorable opinion of socialism than capitalism at least signals that the cold war era conflation of socialism with Stalinism no longer holds sway.

At an intellectual level, the same is true. Marxists have gained a measure of mainstream exposure: Foreign Policy turned to Leo Panitch, not Larry Summers, to explain the recent economic crisis; and thinkers like David Harvey have enjoyed late career renaissances. The wider recognition of thought "left of liberalism" – of which the journal I edit, Jacobin, is a part – isn't just the result of the loss of faith in mainstream alternatives, but rather, the ability of radicals to ask deeper structural questions and place new developments in historical context.

Now, even celebrated liberal Paul Krugman has been invoking ideas long relegated to the margins of American life. When thinking about automation and the future of labor, he worries that "it has echoes of old-fashioned Marxism – which shouldn't be a reason to ignore facts, but too often is." But a resurgent left has more than worries, they have ideas: about the reduction of working time, the decommodification of labor, and the ways in which advances in production can make life better, not more miserable.

This is where what's evolving, however awkwardly, into the 21st-century socialist intellectualism shows its strengths: a willingness to present a vision for the future, something deeper than mere critique. But intellectual shifts don't mean much by themselves.

A survey of the political landscape in America, despite Occupy's emergence in 2011, is bleak. The labor movement has shown some signs of life, especially among public sector workers combating austerity, but these are at best rearguard, defensive struggles. Unionization rates continue to decline, and apathy, not revolutionary fervor, reigns.

Marxism in America needs to be more than an intellectual tool for mainstream commentators befuddled by our changing world. It needs to be a political tool to change that world. Spoken, not just written, for mass consumption, peddling a vision of leisure, abundance, and democracy even more real than what the capitalism's prophets offered in 1939. A socialist Disneyland: inspiration after the "end of history".