We have worked on this book for longer than we care to admit. One of its pleasures has been interchange with colleagues who read and commented on all or parts of the book and who enriched it in the course of conversation with us. Although we did not always embrace their suggestions or satisfy their challenges, we particularly want to thank Jeff Henig, Hank Levin, Deborah Stone, Hugh Heclo, Howard Rifkin, Ruth Messinger, Sue Urahn, Michael Delli Carpini, Michael Lipsky, Miles Rapoport, David Callahan, David Smith, Kate Kraft, Stephen Heintz, Walter F. Mondale, J. Brian Atwood, Judy Feder, Jennifer Hochschild, Jon Oberlander, and Michael Gusmano. We are grateful to the Ford Foundation for a grant that got this project under way. Three anonymous reviewers gave us insightful feedback and encouragement, as did two superlative social science editors — Ben Page (series editor) and John Tryneski (Chicago's Social Science editorial director) —who admirably uphold the traditions of intellectually engaged editors. We alone are responsible for errors in and limitations of the book.