David W. Brady is Bowen H. and Janice Arthur McCoy Professor of Political Science in the Stanford Graduate School of Business. Among his books are Continuity and Change in House Elections (with John F. Cogan and Morris P. Fiorina, Stanford, 2000) and Critical Elections and Congressional Policy Making (Stanford, 1988). Mathew D. McCubbins is Professor of Political Science at the University of California, San Diego. His work on Congress includes Legislative Leviathan (with Gary W. Cox).