This article introduces a categorization theory of spatial voting.

Voter Categorization Theory

Our theory suggests voters perceive political stances through coarse classifications defined by the ideological center.

Behavioral Findings

* Voter behavior significantly diverges from standard utility maximization models along ideological continua.

* Voters exhibit preference discontinuities, favoring parties on their side more than traditional spatial models predict.

Mechanism and Implications

This challenges the existing focus on proximity rules alone. Our analysis shows these rules primarily help distinguish parties within the same side of the center. Importantly, voter party evaluations contain a nontrivial identity component that generates in-group biases not accounted for by standard spatial models.