Nathan P. Kalmoe is associate professor of political communication in Louisiana State University’s Manship School of Mass Communication and Department of Political Science. He is the author of With Ballots & Bullets: Partisanship & Violence in the American Civil War and coauthor of Neither Liberal nor Conservative: Ideological Innocence in the Mass Public. Lilliana Mason is associate research professor of political science at Johns Hopkins University’s SNF Agora Institute and Department of Political Science. She is author of Uncivil Agreement: How Politics Became Our Identity.