This thoughtfully updated revision of a classic text sheds new light on the potential sociological and biological differences that result in deep, seemingly unbridgeable political divisions. Renowned social scientists and experts in biopolitics, John R. Hibbing, Kevin B. Smith, and John R. Alford present overwhelming evidence that political opinion is shaped not just by cultural background or information bias but is rather the result of diverse psychological, physiological, and genetic traits. This new edition shifts the emphasis from differences between the political left and the right (liberals and conservatives) as they have traditionally been understood and explores specific brands of liberalism and conservatism such as ardent supporters of politicians such as Donald Trump. An essential read for students and scholars of political psychology and party politics, this book invites the reader to reconsider their perspectives on public opinion and partisan conflict. John R. Hibbing is the Emeritus Foundation Regents University Professor of Political Science and Psychology at the University of Nebraska-Lincoln. He has been named a Guggenheim Fellow, a NATO Fellow in Science, and a Fellow in the American Association for the Advancement of Science. Kevin B. Smith is the Leland and Dorothy Olson Professor of Political Science at the University of Nebraska-Lincoln. He is an award-winning teacher and the author of nine previous books, including The Ideology of Education: The Market, the Commonwealth, and America’s Schools and Analyzing American Democracy . John R. Alford is Professor of Political Science at Rice University. He has published in areas as diverse as coal mine safety, pro-natalist policies in Eastern Europe, and congressional elections. He has also been active as a consultant and expert witness in the area of redistricting and election law.