Dependency theory in the tradition of Ruy Mauro Marini emphasized the super-exploitation of labor and helped direct attention to capital’s quest to further expropriate part of the consolidated consumption fund historically won by labor. Marini’s work represented a significant departure from the ECLAC conception of vulnerabilities exhibited by developing countries, opting instead to take Lenin’s theory of imperialism as the key point of departure for analyzing dependency. Marini was critiqued on intellectual grounds by more conservative dependency theorists such as Cardoso, Serra and Cueva, consequently blunting the critical leading edge of dependency theory. This exploration of Marini’s critical Marxist formulation helps contextualize the continuing relevance of dependency theory for comprehending the ongoing class struggle and large-scale transformations of capitalism in 21st century Latin America.