Electoral Acceleration: The Effect of Minority Population on Minority Voter Turnout

Political outcomes are well understood to depend on the spatial distribution of citizen preferences. In this paper, we document that the same holds for the individual decision to be politically active. Using both cross-sectional and longitudinal evidence on turnout, we show that citizens are more likely to vote if they live in a jurisdiction with a larger number of persons sharing similar political preferences. As a result, changes in the identity of a district's median citizen lead to even larger changes in the identity of its median voter, a phenomenon we term electoral acceleration. We present evidence that electoral acceleration is in part due to the structure of media markets. Candidates find it easier to direct campaign efforts at larger groups because many existing media outlets cater to this audience.