Contemporary migratory flows take place within a conjuncture of fear and fight against human mobility seen as “external threat”: this view generally guides public debates and policies on individual rights and freedom of migrants. This paper addresses the legal treatment of migrants in Brazil from a historical perspective, showing a reduction in the population concentration and an imbalance between newcomers and Brazilians living abroad. The national regulation of migration flows, inspired by the main international sources of migrants' rights, has recently gone through a paradigm shift from security to solidarity. In a historic and unanimous vote, the new Migration Law has been approved, which instead of stressing exclusively the importance of border controls began to focus on welcoming foreigners. The executive branch's defensive reaction was automatic, with the issue of a decree regulating the law. The effects of this tension have invested the Judiciary, including some cases considered by the Supreme Federal Court. In the end, a brief comparison is made with the two main Western legal systems on immigration, in the United States and the European Union: the Brazilian trajectory shows some significant transformations experienced by the Constitutional State.