Recent studies have found that democratization and reductions of socioeconomic ethnic inequality generally show a positive association. Yet, the causal mechanisms behind the co-variation are not well understood. Moreover, the identified relationship covers considerable heterogeneity, with some transitions to democracy being followed by significant distributive change and others not. To shed additional light on the relationship, this article examines the political and social dynamics related to five democratic transitions. Three led to reduced socioeconomic inequality across ethnic groups, two did not. The "positive" cases (Bolivia, South Africa, and Nepal after 2006) reveal that political empowerment of socioeconomically disadvantaged groups and consequent changes in policies constitute important drivers of reduced ethnic inequalities. In contrast, the "negative" cases (Guatemala and Nepal 1991-2002) demonstrate that democracy only leads to reduced ethnic inequality if democratization is followed by effective mobilization by the previously excluded group(s), and this step might be obstructed by traditional elites.