This article argues that ethnoracial inequalities undermine support for democracy. We develop an original theoretical argument specifying how structural inequalities delegitimize democracy by alienating marginalized group members while also rationalizing forms of hierarchy at odds with democratic principles. Evidence from a large-scale survey experiment conducted among Black and white respondents in the United States shows that exposure to racial inequalities undermines diffuse support for democracy across society even while provoking group polarization in people’s attitudes toward the specific government institutions that allow inequality to persist. Qualitative evidence from the experiment further illuminates the mechanisms linking racial inequality to democratic delegitimation and reveals how underlying thought processes operate differently across groups. The article provides empirical evidence in line with insights from democratic theorists concerning the detrimental consequences racial hierarchies have for democratic citizenship and contributes to growing cross-national conversations about the challenges structural inequalities pose for democracy.