When the United States began its overt military conflict with Iraq in January 1991, the news media focused unceasingly on the Gulf crisis. Using national survey data, we show that this emphasis altered the ingredients of Americans' assessments of George Bush's performance. After the war, assessments were based more on beliefs about Bush's effectiveness in managing the conflict and less on confidence in his handling of other foreign relations matters or the domestic economy. Consequently, Bush's overall performance ratings increased dramatically following the war. We also show that the media's impact on political judgments was regulated by citizens' levels of political knowledge, exposure to political news, and interest in the war. Greater impact was associated with higher levels of knowledge and lower levels of exposure and interest. These findings challenge traditional views of these dimensions of political involvement and support a view derived from contemporary psychological theories of information processing.