Identification of voters with interest groups improves the electoral chances of the challenger

This short paper investigates the consequences of voters identifying with special interest groups in a spatial model of electoral competition. We show that by effectively coordinating voting behavior, identification with interest groups leads to an increase in the size of the winning set, that is, the set of policy platforms for the challenger that will defeat the incumbent. Consequently, our paper points at a novel process through which interest groups can enhance the electoral chances of a challenger.