Political parties do not merely reflect social divisions, they actively construct them. While this point has been alluded to in the literature, surprisingly little attempt has been made to systematically elaborate the relationship between parties and the social, which tend to be treated as separate domains contained by the disciplinary division of labor between political science and sociology. This article demonstrates the constructive role of parties in forging critical social blocs in three separate cases, India, Turkey, and the United States, offering a critique of the dominant approach to party politics that tends to underplay the autonomous role of parties in explaining the preferences, social cleavages, or epochal socioeconomic transf...