How do citizens faced with a complex variety of considerations decide whether or not to tolerate extremist groups? Relying on several survey-experiments, the authors identify and compare the impact on decision making of contemporary information, long-standing predispositions, and enduring values and beliefs. People react most strongly to data about a group's violations of behavioral norms and the implications for democracy of the group's actions. The authors conclude that democratic citizens should have a strong baseline of tolerance yet be attentive to and thoughtful about current...