Mainstream literature in political science confers to institutions a key role in the formation, performance and fall of governments. In the meantime, studies on coalition theories did not, in their majority, escape from this neo-institutionalist approach. Based on the late Mexican constitutional reform which made the formation of coalition governments in the country possible, we shall compile and test most of the arguments on the institutional impacts on coalitions, and test them through the Latin American experiments, using a configurational comparative approach (QCA). As a result, we expect to add nuance to most of the neoinstitutionalist arguments.