Along with the politically active Oberlin community and the left-wing political community in general, this week’s issue of the Review is so inundated with coverage of the Occupy Wall Street protests that I almost hesitate to write any more about it for fear of a complete overload. Much of the progressive movement still seems to be searching for its perspective on the Occupy movement, particularly in academic and sophisticated settings like this campus, oscillating between a raucous encouragement of progressive populism and a snide disregard for the protesters’ vagueness and incoherence. Some progressives have gone so far as to compare the Occupy movement’s perceived lack of seriousness and intellectual depth to that of the Tea Party, and comparisons between the two have become a quickly solidifying storyline within the mainstream media, with many who bemoaned the rise of the Tea Party also bemoaning the rise of the supposed “Tea Party of the Left.”

Establishment pundits like Thomas Friedman of the New York Times have an answer to this dilemma: a mass movement not of the left or right, but of what Friedman calls the “radical center.” Friedman is frustrated that in this political climate, as he tells it, Democrats will be voted out of office for cutting spending when needed and Republicans for raising taxes when needed. Instead, he has thrown his support behind “post-partisan” groups like No Labels and Americans Elect, which would supposedly break the Washington gridlock and promote a “hybrid” agenda incorporating both government- and market-based solutions to economic challenges. Of course, Democrats have consistently agreed to massive spending cuts while Republicans have consistently refused to consider a single cent of increased federal revenue, and the hybrid ideas Friedman advocates are essentially a recapitulation of the Democratic policy platform. But such inconvenient facts never seem to dampen the determination of Friedman and like-minded centrists to declare a plague on both Democrats’ and Republicans’ houses alike.

A useful conceptual tool for understanding this discrepancy is what political scientists call the Overton window. Imagine the window as a range of opinions that are considered acceptable, from stalwarts like “the First Amendment is a good thing” in the middle to more debatable ideas like “the payroll tax cutoff is too low” closer to the edges, with opinions like “Heil Hitler” missing the window entirely. What’s confusing poor Tom Friedman is that the political establishment’s Overton window has moved, encompassing ideas like “no elected Republican can ever support a tax increase” and avoiding ones like “global warming is a universally accepted scientific fact.” In response, the radical center has reoriented itself politically without bothering to change its actual policy preferences, and commentators like Friedman end up rejecting Democratic politicians who share much, if not all, of his practical ideology.

For a good example of how successful Republicans have been at moving the window over time, look no farther than the decades-long debate over health care reform. As recently as the 2006 Massachusetts health care reform effort, Republicans pushed for ideas like the individual mandate that forms the basis of the 2010 Patient Protection and Affordable Care Act, which today’s GOP conventional wisdom holds to be little more than an instrument of socialist tyranny. But the inconsistency runs deeper than that: During the health care debate of the 1970s, Democratic reformers led by Ted Kennedy rejected as too right-wing Richard Nixon’s reform proposal that included a nationwide public health insurance option, an idea the modern establishment has dismissed as too left-wing even for many moderate Democrats.

Still, it’s not only conservatives who have historically benefited from the fickleness of the Overton window. Every morning I look out from my window in Talcott Hall and see a monument dedicated to the radical progressives of the Underground Railroad, who we praise as heroes but who were condemned by the Tom Friedmans of their day in terms much stronger than our modern political establishment uses in criticizing Occupy Wall Street. The abolitionists of the 1850s were so immoderate, so un-centrist, so partisan that they and the Southern fire-eaters on the opposite extreme dragged our country into a civil war that left hundreds of thousands dead — but the consensus has changed so dramatically since then that few would dare claim that the abolitionists weren’t dead right, or their pro-slavery counterparts dead wrong.

So how do realignments like this happen? How do you go about convincing radical centrists like Friedman to accept ideas that a previous era’s radical centrists dismissed as unacceptably extremist? Since committed moderates form their views by essentially averaging the views of their contemporaries, the way to do it is with a hyperpartisan mass movement that skews the average, forcing the discourse in one direction by the sheer power of its numbers and commitment. The Tea Party has been a textbook example of such a movement, tugging the GOP farther and farther rightward on issues like taxation, health care and the environment; now Occupy Wall Street is poised to tug Democratic politicians similarly to the left, if only they will let it. On the other hand, if Democrats form their typical circular firing squad and blast each other apart over ideological semantics and poorly thought out policy ideas, Occupy Wall Street will fade into irrelevance, the goalposts will keep moving to the right and the Republicans will reign ever supreme. To all partisans of the Left, whether engaged and well-informed or merely enraged and motivated: The choice is yours.