In recent years, epidemiology has made a leap from specialized literature to popular discourse. Thanks in part to Malcolm Gladwell's bestselling treatment of "social epidemics," The Tipping Point, nearly every facet of social and political life-from fashion trends and crime waves to global warming and obesity rates-has been described as an epidemic. This paper explores the rise of an "epidemiological imaginary" in which the language of epidemiology proves increasingly persuasive as a way to understand social and political life. This paper explains this imaginary as a reaction to widespread destabilizations of social space, and examines the implicit and explicit political consequences of this way of seeing the world. Ultimately, we argue that the metaphorics of infection resonates with the experience of globalization, but that its political effects depend on its ability to intermix with more concrete political ideologies.