Research examining media effects on political attitudes has put forth broadly conflicting explanations: media use diminishes knowledge and involvement and contributes to political cynicism and declining turnout; media use contributes to learning, political involvement, trust, efficacy, and mobilization. We address these explanations with detailed measures for the Netherlands in 1998. A dual effects hypothesis is supported: regularly watching television news on the public service channels has positive effects on cognition, efficacy, and turnout, whereas regularly opting for commercial television news has negative effects. Viewing behavior thus separates the more knowledgeable, the efficacious, and the politically involved from those who are not, revealing what might be described as a “virtuous circle” for some and a “spiral of cynicism” for others.