Polarization is everywhere. It is, according to the Pew Research Center, “a defining feature of American politics today.” Elected officials, journalists, and political pundits seem to agree that it is a severe problem in urgent need of fixing, maybe even the root of all evil that plagues the United States, from dysfunction in Congress to the decay of social and cultural norms. Many historians, too, have embraced the concept of polarization for its explanatory power: It has emerged as the closest thing to a master narrative for recent American history. In this interpretation, the “liberal consensus” that had dominated mid-twentieth-century American politics and intellectual life—the widely shared acceptance of New Deal philosophy and broad agreement on the desirable contours of society and the pursuit of certain kinds of public good—gave way after the 1960s to an age of heightened tension, dividing Americans into two camps that since then have regarded each other with deepening distrust. Yet too few historians have reflected on the limits and potential pitfalls of using polarization as a governing historical paradigm. It is high time, therefore, to pause to consider the larger implications of approaching the past through the prism of polarization.