John J. DiIulio Jr. is a professor of political science at the University of Pennsylvania and has won each of Penn's most prestigious teaching awards. Previously professor of politics and public affairs at Princeton University, Dr. Dilulio has been a senior fellow and directed research programs at several leading think tanks, including the Brookings Institution. He has been honored with awards from the Association of Public Policy Analysis and Management, the American Political Science Association and other organizations. In addition, he has advised presidential candidates in both parties, served on bipartisan government reform commissions and worked as a senior staff member in the White House. He received his Ph.D. in political science from Harvard University. James Q. Wilson taught at Boston College and Pepperdine University. He was Professor Emeritus of Management and Public Administration at UCLA and, before that, the Shattuck Professor of Government at Harvard University. He wrote more than a dozen books on public policy, bureaucracy and political philosophy. A former president of the American Political Science Association, Dr. Wilson is the only political scientist to win three of the four lifetime achievement awards presented by the APSA. In 2003, he received the Presidential Medal of Freedom, the nation's highest civilian award. Professor Wilson passed away in March 2012 after battling cancer. His work helped shape the field of political science in the United States. His many years of service to this textbook remain evident on every page and will continue for many editions to come. Meena Bose is executive dean for public policy and public service programs in the Peter S. Kalikow School of Government, Public Policy and International Affairs at Hofstra University. She also directs Hofstra�s Peter S. Kalikow Center for the Study of the American Presidency and is the Peter S. Kalikow Chair in Presidential Studies and a professor of political science. The author or editor of several volumes in presidency studies and American politics, Dr. Bose teaches courses on the American presidency, presidential leadership and policymaking and American politics. She taught for six years at the United States Military Academy at West Point, and she is a member of the Council on Foreign Relations. Dr. Bose received Hofstra�s 2020 Teacher of the Year Award in the Kalikow School. She earned her Ph.D. from Princeton University and her B.A. from The Pennsylvania State University. Matthew S. Levendusky is a professor of political science and the Stephen and Mary Baran Chair in the Institutions of Democracy at the Annenberg Public Policy Center at the University of Pennsylvania. He works broadly in political behavior, with a particular focus on political polarization. His work has been recognized with a number of honors, including the Jewell-Lowenberg Award for the best article published in LEGISLATIVE STUDIES QUARTERLY, the best paper award from the JOURNAL OF POLITICS, the Goldsmith Book Prize from Harvard University's Shorenstein Center and the Erik Erikson Early Career Award from the International Society of Political Psychology. He earned his Ph.D. from Stanford University and his B.A. from The Pennsylvania State University.