Acknowledgments: I wish to thank many friends and colleagues for comments, discussions and encouragement: Kanyarat Bhanthumnavin, Luc Bovens, Richard Bradley, Steven Brams, Geoffrey Brennan, Bruce Chapman, Franz Dietrich, John Dryzek, Christian Elsholtz, Wulf Gaertner, Natalie Gold, Robert Goodin, Thomas Kittsteiner, Margaret Meyer, David Miller, Klaus Nehring, Philip Pettit, Ashley Piggins, Clemens Puppe, Alec Stone Sweet, Kamakshya Trivedi, Bertil Tungodden. I am grateful to the anonymous reviewers and the editor of the APSR for very helpful comments and suggestions. My research was supported by the Social and Political Theory Program at the Australian National University, the London School of Economics, and Nuffield College, Oxford.