This paper focuses on mass media’s impact on citizens’ confidence in political institutions. Drawing on research within the field of political science that builds on the discrepancy theory from cognitive psychology, the paper argues that citizens’ preferences of how political institutions should work and the outcomes they should produce moderate mass media’s impact. Building on research of media framing effects on political attitudes an preference-perception model of media effects is developed. The model explains how the relationship between political reality perceptions that trace back to media coverage and political preferences derived by socialization in a political culture accounts for variations in political confidence at the individual level. The paper also develops a distinct set of specific media frames that correspond to a variety of political preferences as well as aspects of political legitimation. The model contributes to further specifications of the relationship between mediated political information and political attitudes.