The idea of the public sphere, of an institutionalized arena of discursive interaction, is central to democratic theory and practice. The modern age has, however, witnessed the erosion of a public realm distinct from the state and the market. In response to this erosion, public realm theory, notably the work of Arendt and Habermas, attempts to theorize the minimal conditions necessary for a discursive realm free of structural coercion or manipulation. The resulting normative conception of the public sphere has come under sharp attack by postmodern theorists, including Foucault, Lyotard, and Baudrillard, who question the basic presuppositions of public realm theory. I examine their objections and show how the public realm theory of Arendt can be viewed as motivated by concerns similar to the postmoderns'. Against Habermas, I argue that Arendt's public realm theory is less concerned with the question of legitimation than with the theorization of an agonistic political subjectivity.