Current research has found ambiguous theoretical and empirical results with respect to the effects of the type of electoral regime on trade policy. The present paper aims to reconcile the different views within a theoretical model. It is shown that the equilibrium level of trade protection can be relatively higher, as well as lower, under a majoritarian electoral rule compared with proportional representation. Trade policy is more (less) protectionist under proportional electoral regimes, as compared with majoritarian institutions, if swing districts are populated by relatively more (less) factor owners with stakes in the exporting sector. It is also shown that politicians optimally apply a lower (higher) level of rent seeking under the majoritarian electoral rule if there are relatively more factor owners in the swing districts with stakes in the exporting (import-competing) sector.