Political communication researchers have devoted a great deal of attention to the role of political advertising, the Internet, and political discussion in civic and political life. In this article, we integrate and extend this research by developing a campaign communication mediation model of civic and campaign participation. Two data sets are merged for this inquiry: (a) content-coded ad-buy data on the placement of campaign messages on a market-by-market and program-by-program basis and (b) a national panel study concerning patterns of traditional and digital media consumption and levels of civic and campaign participation. Exposure to televised campaign advertising is estimated by developing an algorithm based on the market and program placement of specific ads and geocoded survey respondents' viewing of certain categories of television content in which these ads were concentrated. Structural equation models reveal that advertising exposure drives online news use in ways that complement conventional news influences on political discussion and political messaging. However, campaign exposure emphasizing "attack" messages appears to diminish information seeking motivations via broadcast and print media, yet only indirectly and weakly suppresses participation in civic and political life. Further, alternative specifications reveal that our original model produces the best fit, empirically and theoretically. We use these insights to propose an O-S-R-O-R (orientations-stimuli-reasoning-orientations-responses) framework as an alternative to the longstanding O-S-O-R model in communication and social psychology.