Among the measures of the Brazilian’s military dictatorship was the constitution of a legal frame that would guarantee an apparent legitimacy and legality of the 1964 coup. Originated from an empirical research, using a trajectory analysis this paper examines the lawyers’ trajectories named for the Special Commission of 1966. This Commission was hence authorized to draft a new constitution. Though the group's work was unsuccessful, the relationships between these law experts and the executive authorities allow us to understand the origins and shifts of the civilian elites who supported, with their expertise, the military dictatorship.