Sleeping with the Enemy: Effective Representation under Dynamic Electoral Competition

Electoral coalitions between ideologically incompatible parties - among other unconventional electoral strategies - may seem to threaten effective representation, signaling a breakdown of programmatic politics. However, this perspective overlooks parties' and voters' dynamic considerations. We propose and estimate a model of dynamic electoral competition in which a short-term ideology compromise, via an electoral coalition, offers opposition parties (and voters) the opportunity to remove an entrenched incumbent party from office, thus leveling the playing field in the future. This tradeoff provides a previously unrecognized rationale for coalition formation in elections. We take our model to data from Mexican municipal elections between 1995 and 2016 and show that coalitions between parties on opposite ends of the ideology spectrum have served as an instrument of democratic consolidation.