Elections around the globe attest to the persistence of polarization in democratic politics. Popular support for antagonistic elite strategies defies standard predictions of ideological convergence. This paper develops a new solution to the theoretical puzzle: The centrifugal drive in representative democracy is a byproduct of voters’ disposition to evaluate policy platforms on the basis of issue positions that they dislike—to wit, negative voting. While reasonable individually, this behavior backfires collectively as elections dominated by negativity produce more polarized legislatures. Quite tragically, party polarization ultimately reflects an uncoordinated struggle of the electorate to avoid the worst rather than to pursue the best. Support for these claims comes from a theoretical model and a large comparative analysis of vote choice and party platforms. The evidence also favors the negativity model over earlier spatial models of elections. In light of negativity, normative concerns about polarization and democratic representation stand to be reconsidered.