Abstract. In the context of politics, emotions and facts work together to shape opinions about political candidates. While there is considerable research on motivated reasoning about political issues, there is less attention to how affect and rationality combine in the hybrid world of new media. This study examined the interaction of social media comments about politicians with more traditional information sources. Participants were exposed to political candidates' Facebook news feeds, to news articles about the candidates, and to a political speech. The order of exposure was varied and measures of both knowledge and emotion were taken. When social media was encountered before news about a political candidate, it influenced feelings toward the candidate but did not influence personal mood or perceived knowledge. In contrast, when social media was encountered before information unrelated to the candidates, it negatively influenced all dependent measures. The findings are discussed in terms of motivated reasoning theories, Papacharissi's concept of "affective publics," and the implications for civic participation in the new media era.