Bruce E. Cain is Robson Professor of Political Science, University of California, Berkeley, and Director, Institute of Governmental Studies, University of California, Berkeley. He is the author of "The Reapportionment Puzzle "(California, 1984) and coauthor of "The Personal Vote "(1987) and "Congressional Redistricting "(1992). Elisabeth R. Gerber is Professor of Public Policy and Director of the State and Local Policy Center, Gerald R. Ford School of Public Policy, University of Michigan. She is the author of "The Populist Paradox: Interest Group Influence and the Promise of Direct Legislatio...