The cost of voting is higher for socially and economically disadvantaged communities. We know that their crowded polling stations have longer lines, and those who vote at such stations once are less likely to vote again in the future. However, we do not know whether the implied effect of station size is causal. With an instrumental variables approach to discontinuities in station size in Turkey, this study provides the strongest causal evidence yet: station size decreases not only voter turnout but incumbent vote share. If incumbents are punished for crowded stations in the same election, then there would be strong incentives for governments to distribute the resources for electoral management more equally, increasing the participation of the disadvantaged communities in elections.