This article investigates the impact of Communist historical legacies on the variation of sub-national regimes in a federal state. It focuses on the Russian Federation and studies the role of sub-national variations of membership rates in the Communist Party of the Soviet Union (CPSU) during the 1970s and 1980s as a predictor of regional democracy in Russia in the 2000s. Using a unique dataset collected by the authors, the article shows that past CPSU membership rates continue to have a significant and negative impact on democracy at the sub-national level. The article also investigates possible mechanisms of this effect and links them to the persistence of Soviet bureaucracies and their role in exercising control over regional economies. These findings contribute to understanding the complex nexus of federalism and sub-national democracy and to the study of the role of communist legacies in democratisation.