William Howell is the Sydney Stein Professor in American Politics at the University of Chicago. He holds appointments in the Harris School of Public Policy, the Department of Political Science, and the College. He has written widely on separation-of-powers issues and American political institutions, especially the presidency. His recent research examines how domestic political institutions constrain the president's ability to exercise military force abroad. He is currently working on a book, tentatively entitled The Wartime President, that examines the impact of war on the power that U.S. presidents wield at home. William is the co-author (with Jon Pevehouse) ofWhile Dangers Gather: Congressional Checks on Presidential War Powers (Princeton University Press, 2007); author of Power without Persuasion: The Politics of Direct Presidential Action (Princeton University Press, 2003); co-author (with Paul Peterson) of The Education Gap: Vouchers and Urban Schools (Brookings Institution Press, 2002); co-editor (with George Edwards) of The Oxford Handbook on the American Presidency(Oxford University Press, 2009); and editor of Besieged: School Boards and the Future of Education Politics(Brookings Institution Press, 2005). His research also has appeared in numerous professional journals and edited volumes.