Recent research has shed light on the impact of pre-electoral coalitions on government formation in presidential democracies. However, the fact that pre-electoral coalitions are not automatically transformed into coalition cabinets has often gone under the radar. In this article, I argue that the importance of pre-electoral pacts for government formation depends on the degree of legislative polarization. When parties are distant from one another in the ideological spectrum, presidents face more difficulties in breaking away from the pre-electoral pact and rearranging their multiparty alliances. Conversely, when polarization is not pervasive, presidents have more leeway to build coalition cabinets different from the ones prescribed by pre-electoral coalitions. Drawing on a dataset of 13 Latin American countries, the results support my claim and suggest that the relationship between government formation and the concession of office benefits for pre-electoral coalition members is more nuanced than previously assumed.

This research note contributes updated and extended point estimates of the ideological positions of Brazilian political parties and novel estimates of the positions of all presidents since redemocratization in 1985. Presidents and parties are jointly responsible for the operability of Brazil’s version of coalitional presidentialism. Locating these key political actors in a unidimensional left–right space over time reveals rising challenges to the institutional matrix, particularly since 2013. Ideological polarization among parties has sharply increased, presidents have become more distant from Congress, and the political center has become increasingly vacated. Coalitional presidentialism is being subjected to unprecedented ideological stress as President Luiz Inácio Lula da Silva begins his third term in office.

When and why do legislatures impeach presidents? We analyse six cases of attempted impeachment in Paraguay, Brazil and Peru to argue that intra-coalitional politics is central to impeachment outcomes. Presidents in Latin America often govern with multiparty, ideologically heterogeneous coalitions sustained by tenuous pacts. Coalitions are tested when crises, scandals or mass protests emerge, but presidents can withstand these threats if they tend to allies’ interests and maintain coalitions intact. Conversely, in the absence of major threats, presidents can be impeached if they fail to serve partners’ interests, inducing allies to support impeachment as acts of opportunism or self-preservation.