The Introduction contextualizes the volume’s objectives, introduces its research questions and defines basic terms. A starting point is the finding in the literature that migration is ’merely’ one of several contributing factors to democratic decay, in the sense that (authoritarian) populists have seized on the ‘migration crisis’ to further undermine constitutional democracy. Yet, in our estimation the relationship between the three forces that reside at the core of this volume – populism, democratic decay and migration – is more multifaceted and complex. After engaging with this relationship, the Introduction examines avenues for legal resilience against (authoritarian) populism. By drawing inspiration from the scholarship on environmental law, a definition of legal resilience is proposed, on the basis of which a two-stage analysis is developed to evaluate the possibilities and limitations of legal resilience against (overly) restrictive migration laws and policy. In a first stage, it should be determined how resilient the legal system itself has been in the face of populist onslaught. In the second stage, once we know how resilient the legal system as a whole has proven to be, we can identify the extent to which it provides for legal resilience against restrictive migration laws and policies.