The paper explains how political coalitions in the Brazilian government obstruct corruption investigations conducted by the Congress (through Parliamentary Investigation Committees). We use a new research method to political science, process-tracing method, which unveils causal relations in a sequence of events and highlights the original cause of the final event.
We analyze three Parliamentary Investigation Committees in recent Brazilian history: 1) the Paulo César Farias episode (1992); 2) the so-called banks committee (1999); 3) the 'Mensalão' corruption case (2005). We chose these episodes following three criteria: i) they cover finished government mandates, Collor, Cardoso and Lula; ii) they were motivated by public complaints; iii) they mobilized both the government and the opposition during their existence.
We explain that the structure and depth of the coalition define its success in obstructing corruption investigations and point to the channels through which the coalition acts: bargaining, logroll policies, and threats or sanctions.
Keywords: corruption; political behavior; parliamentary investigation committee; process-tracing