Elisabeth Gidengil, André Blais, Neil Nevitte and Richard Nadeau
The most obvious place to look for the effects of election campaigns is in the realm of persuasion. After all, this is what election campaigns are about: the strategic efforts of parties and candidates to gain votes by persuading as many voters as possible to vote for their party's candidates. We typically think of persuasion as getting voters to change their opinions of the parties, the leaders or the issues of the day, but this is too narrow a conception. In this chapter we focus on a more subtle but none the less important form of persuasion: getting voters to change the bases on which they decide their vote.
This is precisely what motivates the parties' struggle to control the election agenda. Parties seek to emphasize considerations that will help them-be it a popular leader or an issue on which they possess a recognized expertise-and to downplay those that will hurt (Budge and Farlie 1983; Petrocik 1996; Nadeau et al. 2000a). From the parties' perspective, then, election campaigns can be conceptualized as a competition for control of the agenda. Political parties, however, are not the only players in this agenda-setting competition. The media are also potentially critical players (Semetko 1996; Norris et al. 1999). Political parties rely on the media for communicating their core messages to voters, but the media do not serve simply as a neutral transmission belt between the parties and the voters. In a very literal sense, they mediate the campaign communication flows, highlighting some messages and downplaying others. This is the essence of the media's power to prime (Iyengar and Kinder 1987).
Priming can be thought of as 'an extension of agenda-setting' (Ansolabe-here et al. 1991:127; Semetko 1996:275). Indeed, Miller and Krosnick (2000) have argued that priming occurs via agenda setting. 1 Agenda setting refers to the media's power to influence the public agenda (McCombs and Shaw 1972). In the context of elections, the basic proposition is that the more attention the media pay to an issue, the greater will be its perceived electoral importance. Priming occurs when extensive media coverage leads voters to attach more importance to a given consideration in deciding their vote. Priming can lead people to change their minds, not because they have