How do individuals form and revise their judgments about political candidates, issues, and parties? How do they make a choice in a strategic environment? The book develops a psychological model of political judgment that integrates contemporary theories of political behavior and explores its implications on judgment and choice in political elections and game theoretic environments. Specifically, it examines the changes in candidate evaluation observed over the course of a presidential election campaign and the dynamics of cooperation observed in classic repeated PD game experiments. In effect, it demonstrates that a single set of well-established, basic psychological processes underlying judgment and choice can together account for the observed dynamics - both responsiveness and persistence - of candidate evaluation and the emergence of cooperation in the repeated PD game.