Does benefit competition affect voters' support for immigrants' social rights? While scholars in political economy expect that benefit competition lowers support among the poor, the evidence is limited. This seems to be largely due to the reliance on highly aggregated analyses and the neglect of the institutional context in which individuals form their preferences. This article argues that lower-income voters are more likely to reduce their support due to competition when benefit eligibility depends on income. Using individual-level panel data from the Netherlands and a novel way to measure benefit competition, the study shows that lower-middle-income voters become less supportive of immigrants' social rights when more social housing in their municipality is allocated to refugees. By contrast, competition does not reduce support among the rich or the very poor. The findings suggest that benefit competition can erode support for immigrants' social rights and influence electoral politics.