Presidentialization of Japanese Politics? Examining Political Leader Evaluations and Vote Choice

In recent years, the impact of party leaders on voting behavior has attracted increasing attention, leading some scholars to identify a phenomenon of 'presidentialization'. Many extant studies of this topic in Japan are limited to one or two electoral cycles. In order to trace long-term trends, this paper analyses longitudinal survey data to investigate the existence and magnitude of the effect party leader evaluations exert on vote choice in Japan. Empirical results show that while only dominant and forceful personalities substantially influenced voters' likelihood of supporting their parties in the 1980s and 1990s, by the 2000s assessments of most major party leaders had a significant impact on their parties' electoral performance. In short, party leaders affect vote choice due not to their personalities, but instead to the position they hold. We also test the hypotheses that the association between leader appraisal and voting behavior would be particularly conspicuous among voters who lack party identification and those who are most heavily exposed to media reportage. Analysis reveals that (1) independent voters are not more likely to vote on the basis of leader evaluations than partisans; (2) a leader effect is found more frequently among voters with greater exposure to election coverage on television.