College is a key pathway to political participation, and lower-income individuals especially stand to benefit from it given their lower political participation. However, rising inequality makes college disproportionately more accessible to high-income students. One consequence of inequality is a prevalence of predominantly affluent campuses. Colleges are thus not insulated from the growing concentration of affluence in American social spaces. We ask how affluent campus spaces affect college’s ability to equalize political participation. Predominantly affluent campuses may create participatory norms that especially elevate low-income students’ participation. Alternatively, they may create affluence-centered social norms that marginalize these students, depressing their participation. A third possibility is equal effects, leaving the initial gap unchanged. Using a large panel survey (201,011 students), controls on many characteristics, and tests for selection bias, we find that predominantly affluent campuses increase political participation to a similar extent for all income groups, thus leaving the gap unchanged. We test psychological, academic, social, political, financial, and institutional mechanisms for the effects. The results carry implications for the self-reinforcing link between inequality and civic institutions.