The dynamics of campaign issue agendas

I argue that candidates shape their issue agendas-the sets of related issues on which they focus-in part in response to the issue agendas of their opponents and that competitive campaigns stimulate candidates to respond to one another at higher rates. I test my theory of candidate interaction using weekly advertising data at the media market level from 146 statewide elections-54 gubernatorial and 92 U.S. Senate contests-from six election years and across all 50 states. I find that candidates systematically respond to one another's issue agendas and do so to a greater extent in competitive elections than in noncompetitive elections.