This coming Monday, Sept. 17, is the first anniversary of the day when protesters gathered in Lower Manhattan’s Zuccotti Park under the banner of Occupy Wall Street. The occupation was first dreamed up by Kalle Lasn and Micah White, the close collaborators behind Adbusters, a slickly produced, high-art magazine that uses the tools of commercial culture to make the case against capitalism. Having decided that America needed an uprising akin to those that had shattered authoritarian governments across North Africa, Lasn and White chose a date, created an arresting image emblazoned with the Occupy Wall Street slogan, reached out to potential collaborators and then watched as their creation seized the imagination of millions of Americans.

One year on, the encampments that had sprung up in Lower Manhattan and in cities, college campuses and foreclosed homes across the country have for the most part been abandoned. And so at least some observers are inclined to think, or to hope, that the Occupy movement has been of little consequence. That would be a mistake. Occupy’s enduring significance lies not in the fact that some small number of direct actions continue under its banner, or that activists have made plans to commemorate “S17” in a series of new protests. Rather, Occupy succeeded in expanding the boundaries of our political conversation, creating new possibilities for the American left.

As our slow-motion economic crisis grinds on, it is worth asking: How might these possibilities be realized? For some, Occupy was a liberating experience of collective effervescence and of being one with a crowd. As one friend put it, it was “the unspeakable joy of taking to the streets, taking spaces, exploring new relations and environments” that resonated most. For others, it created a new sense of cross-class solidarity. Jeremy Kessler, a legal historian who covered the Occupy movement for the leftist literary journal N + 1 and the New Republic, senses that it has already shaped the political consciousness of younger left-liberals. “There is more skepticism towards the elite liberal consensus,” and so, “for instance, there is more support for the Chicago teachers union and more wariness towards anti-union reformers.” Ideological battle lines have in this sense grown sharper. Yet it is still not clear where Occupy, and the left, will go next.

Perhaps the most politically fruitful path for the American left would be to go back to the future – to draw on the lessons of the Populists of the William Jennings Bryan era, who sought to unite farmers and industrial workers against the stranglehold of Eastern capital. Back then, the Populists failed, as the interests of industrial workers were more closely tied to their bosses than to those of highly indebted smallholders living in the prairies. Now, however, millions of middle-income households struggle under the burden of underwater mortgages.

In the latest issue of the Nation, David Graeber, the anarchist anthropologist considered an intellectual leading light of the Occupy movement, argues that the “financialization” of the economy should be understood as “an enormous engine of debt extraction,” through which the 1 percent extracts wealth from the 99 percent. Rather than champion specific policies designed to reduce the burden of debt, Graeber calls for a campaign of mass resistance devoted to delegitimizing what he calls “Mafia capitalism.” While Graeber’s language is bracing, and it will undoubtedly appeal to at least some radicals who hope to keep the spirit of Occupy alive, it is not obvious that his idea of mass resistance can build a mass movement.

But might a softer version of Graeberism succeed? As the Georgetown University historian Michael Kazin argues in The Populist Persuasion, American populist movements have traditionally pitted the producing majority against a parasitic elite. That is one reason why “We Are the 99 Percent,” the slogan coined by Graeber and his allies, has proved so resonant: It invokes older American political traditions.

And the case for placing debt at the heart of our politics is stronger than you might think. As the heterodox economic thinkers J.W. Mason and Arjun Jayadev recently observed, household debt has climbed from 50 percent of GDP in 1980 to 100 percent just before the financial crisis. Yet according to Mason and Jayadev, this sharp increase does not primarily reflect an increase in borrowing. Had interest rates, growth and inflation remained the same in the three decades following 1980 as they had in the three decades preceding 1980, household debt levels would have actually decreased. One of the central problems, Mason and Jayadev argue, is that inflation levels decreased faster than households could decrease their borrowing levels. Back in 2009, Christopher Hayes, author of The Twilight of the Elites and host of MSNBC’s Up with Chris Hayes, argued that “a period of moderate, sustained inflation” was essential to addressing America’s economic woes. While this argument seems very technocratic, it has the virtue of speaking directly to the challenge of household debt.

The latest Census data indicates that real median household income in the United States has fallen to levels last seen in 1995. Income inequality, meanwhile, has increased. It is easy to imagine that healthy gains in median household income would mitigate concerns about income inequality as such. But instead, sluggish wage and household income growth have fueled a great deal of anxiety and resentment. Millions of households that had hoped and expected to be climbing the ladder to middle-class prosperity instead find themselves burdened by debt. If the political right and center can’t find a way to revive economic growth and to create shared prosperity, the future might very well belong to Occupy.

PHOTO: Occupy Wall Street protesters relax on a tree at Marshall Park prior to the start of the Democratic National Convention in Charlotte, North Carolina September 3, 2012. REUTERS/John Adkisson