The article analyses the evolution of the debate on socioeconomic vulnerability both in the United States of America and in France, as well as presenting final comments on the Brazilian present time. In the North-American study, the discussion is openly political-ideological making guilty or not the victims for their marginalization and anomy making use of the concept of underclass, what has made some authors regard the so-called well-being programs as responsible for promoting idleness and family disorganization. In the French study, on the contrary and following the republican tradition, both the diagnosis and proposals emphasize the need of strong state presence to provide means of (re)inserting the marginalized groups. Polemic arises around concepts such as social exclusion and defiliation. The essay doesn't aim at making a critical balance of literature, but making use of seminal works it intends to show the parameters acquired by the theoretical and empirical problem depending on the particularities of each national political ambience; that is when final comments on the Brazilian society are made.
Exclusion and social vulnerability; Defiliation; underclass; (Under)citizenship