Abstract: Models of political failure have been criticized for implicitly assuming the irrationality of voters. (Wittman 1998, 1995, 1989; Coate and Morris 1995) Building on Caplan's (1999a, 1999b) model of "rational irrationality," the current paper maintains that the assumption of voter irrationality is both theoretically and empirically plausible. It then examines microfoundational criticisms of four classes of political failure models: rent-seeking, pork-barrel politics, bureaucracy, and economic reform. In each of the four cases, incorporating simple forms of privately costless irrationality makes it possible to clearly derive the standard conclusions. It is a mistake to discount the empirical evidence for these models on theoretical grounds.