How is the quality of public education affected by the presence of private schools for the rich? Theory and evidence suggest that the link depends crucially on the political system. We develop a theory that integrates private education and fertility decisions with voting on public schooling expenditures. We find that the presence of a large private education sector benefits public schools in a broad-based democracy where politicians are responsive to low-income families but crowds out public education spending in a society that is politically dominated by the rich. The main predictions of the theory are consistent with state-level data and micro data from the U.S. as well as cross-country evidence from the Programme for International Student Assessment study.