A prominent avenue of the political campaign's influence on voters is through the nature of its issue content. Political science research has shown that the issues discussed by the candidates and the news media are more likely to become voter priorities, have a greater influence on voting behavior, and also shape what issues candidates address after they are elected. As such, scholars now argue campaigns are less a debate over issues than a fight over what issues to debate. However, despite their prominent influence, theoretical attempts to explain how campaign agendas develop are few, and those that do exist lack firm empirical support.
I seek to clarify how campaign agendas develop by examining how the agendas of candidates, the news media, and voters interact during campaigns. I offer a new perspective of campaign agenda formation that focuses on two attributes of these interactions. First, I suggest that the news media's greater credibility and pervasiveness give them a greater ability to influence voter agendas. Additionally, I argue that news media issue coverage, combined with persuasive candidate rhetoric, can also shape voter evaluations on such issues, especially among swing voters.
I consequently argue that candidate needs to persuade voters are an under-emphasized component of campaign strategy and that an agenda-setting strategy also has costly consequences for candidate efforts at persuasion. Instead of agenda-setting, candidates form their agendas in response to the news media's issue attention in order to shape news coverage and prevent harmful persuasive environments. By making their case on those issues featured within news media coverage, candidates attempt to win over swing voters on such highly salient issues.
I test the theory in three parts of this dissertation. I provide the first known test of reciprocal agenda dynamics and show how the national news media drove candidates and the voters to focus on a select group of issues during the 2000 presidential campaign. I then demonstrate that Bush and Gore's rhetorical responses to the news media's agenda were influential in shaping voter opinions. Finally, I expand the analysis to Senate campaigns of 2000 and 2004 and demonstrate how candidates increasingly focus on issues as they gain coverage within the news media. Both of the theory's expectations are supported, as the news media show a prominent influence on candidate and voter agendas.
On the whole, this persuasion-based theory of campaign agenda formation provides a new and much needed perspective on how the goals and abilities of the news media and candidates interact to create the rhetorical dynamics we observe within political campaigns. The theory applies the known moderators of agenda setting and persuasion within the political behavior literature to derive a better understanding of the influence, incentives, and behavior of candidates and the news media.