Abstract The EU has not yet found effective answers to constitutional crises in its Member States, in particular Hungary and Poland. Due to systemic problems of compliance with the common values of Art. 2, the legitimacy of the EU constitutional order and its smooth functioning are under threat, but the EU lacks instruments of direct enforcement and coercion. Several authors have therefore proposed to ?federalize? EU mechanisms and to guarantee to EU institutions, in particular the Court of Justice, more powers to intervene vis-?-vis Member States. However, the current Treaty framework presents a series of obstacles to federal-like enforcement. Solutions to national crises must ultimately respect the constitutional balance between the Union and the Member States.