David W. Brady is Bowen H. and Janice Arthur McCoy Professor of Political Science and Leadership Values at Stanford University. His books include "Revolving Gridlock" (1998), "Critical Elections in the U.S. House of Representatives" (Stanford, 1988), and "Party, Process, and Political Change in Congress" (Stanford, 2002). "Mathew D. McCubbins is Professor of Political Science at the University of California, San Diego. His books include "The Logic of Delegation," "Legislative Leviathan," and "Party, Process, and Political Change in Congress" (Stanford, 2002)."