Terms like ‘Islamo-fascism’, the ‘anti-totalitarian’ case for war in Iraq and the description of religiously motivated political extremism as a ‘new totalitarianism’ were all remarkable features of the political discourse organised around the response to the events of 11 September 2001. They share in common the attempt to ground political commitments and allegiances in two morally charged political languages: anti-fascism and anti-totalitarianism. But why did they fail to connect with the public imagination? This article argues that they were not constructed for present purposes so much as appropriated. Yet their projected consumption by a broader public turned on the feasibility of effecting conceptual change to accommodate new meanings and applications. The failure, in this case, to meet the standards thereby required suggests that an important dimension of the response to September 11th is the failure of political argument. It is proposed that this has implications more broadly for the relation between political theory and political rhetoric.