Why Pre-Electoral Coalitions in Presidential Systems?

Why do political parties join coalitions to support other parties' presidential candidates if presidents, once elected, are not bound to their pre-electoral pledges? This article argues that policy agreements made publicly between coalition partners during the campaign help parties pursue policy goals. However, parties cannot use pre-electoral coalitions to secure access to patronage, pork and government benefits under the control of presidents because they cannot hold presidents accountable to these agreements. Quantitative analysis of Latin American electoral coalitions demonstrates that political parties are more likely to form presidential electoral coalitions as the ideological distance between them decreases. Yet presidential electoral coalitions tend not to include non-programmatic political parties, even though such office-oriented parties are unconstrained by ideological considerations.