Democratic governance in the modern world presumes regular elections in which the rights of citizenship include, in principle, equal participation and collective influence over the composition of government. For individuals, “casting a ballot is, by far, the most common act of citizenship in any democracy” (Verba, Scholzman, and Brady, 1995:23). The right to vote also provides the foundation for other political and social rights of individuals and groups. At the aggregate level, election outcomes are an important causal factor behind national policy making (Castles, 1982; Blais, Blake, and Dion, 1996; Powell, 2000; Erikson, MacKuen, and Stimson, 2002:Chap. 7). For example, the institutional characteristics of welfare state regimes have been shown to be influenced by the share of the vote won by left-wing or other party families (e.g., Esping-Andersen, 1990; Hicks, 1999; Huber and Stephens, 2001).

Not surprisingly, given their importance in democratic capitalist societies, elections are also influenced by inequalities in the amount of power and status possessed by different groups. The impact of such inequalities on democratic governance has accordingly been a central topic of investigation in political sociology. Political divisions along class, religious, racial and ethnic, linguistic, national, or gender lines have often led to enduring patterns of conflict in party systems or political institutions. Indeed, the investigation of these divisions helped to define some of the central contributions of the post-World War II generation of political sociology (e.g., Berelson, Lazarsfeld, and McPhee, 1954; Lipset, 1960; Alford, 1963; Lipset and Rokkan, 1967a).