This chapter demonstrates that the dynamics of vote choice described in the previous chapter are caused by the discussion and social ties described in Chapter 2. During campaigns, discussion with disagreeing partners tends to induce preference change in voters, while discussion only with agreeing partners reinforces vote intentions, causing preference stability. The chapter illustrates this relationship at multiple levels of analysis, estimating relationships in the Brazilian and Mexican panel surveys in ways that address threats to causal inference. Quotations from the qualitative data also reveal social influence in action, showing vividly that many voters defer to their more politically knowledgeable social ties. In short, the votes cast on election day in Brazil and Mexico are socially informed. The chapter also shows that the social influences that occur during campaigns determine who wins elections. Candidates whose mid-campaign supporters encounter high rates of disagreement from social ties struggle to hold on to these voters through election day. These voters' preferences are less reinforced in conversation, so many switch to different candidates. The candidate they previously supported collapses in the polls.
Media and campaign effects on vote choice at national elections in Europe: A review of a multilingual research landscape Medien- und Kampagneneffekte auf Wahlentscheidungen bei nationalen Hauptwahlen in Europa: Literaturbericht über eine vielsprachige Forschungslandschaft
