This article analyzes the microfoundations of support for governors in Brazil based on a decision model in which deputies attempt to reduce their electoral risks. This model considers the effects of the individual backgrounds of legislators, party strength, and the dynamics of political competition in states. We used ordinary least square regression models to estimate the chances of a legislator to adopt an oppositional stance. The results confirm the multidimensional nature of the government-building process in Brazil. Adhesion is not only coordinated on a partisan basis, but it is also shaped by perceptions of electoral risks, as well as by expected rewards that different political careers and partisan linkages shape.