This volume grows out of the well-documented psychological impulse to bring information to bear on sources of anxiety. In politics, as in other realms of life, anxiety triggers a quest for information. Perceived threats focus the attention (Marcus, Neuman, and MacKuen, 2000). Anxious citizens take more interest in politics, have more motivation to learn, and weigh the information they collect more judiciously (Marcus and MacKuen, 1993, MacKuen et al, 2010, Albertson and Gadarian, 2015). In these respects, worried citizens are better citizens (Brader, 2005, Valentino et al, 2008).