There is currently a widespread view that the EU is in crisis. This crisis is not only financial, but, most importantly, it touches upon the founding principles of the Union as set out in Article 2 TEU. Among them, a principle that has served as the cornerstone of European integration already from its early stages seems particularly threatened: the rule of law. Due to endemic corruption, weak institutional capacities, or insufficient resources at the administrative or judicial levels, some EU Member States present so grave deficiencies in guaranteeing the rule of law that their conformity with basic EU standards is seriously questioned. Although it is obvious that the EU cannot stay inactive in the face of such grave deficiencies, it remains unclear how potential responses fit with the overall EU constitutional framework. This article aims at contributing to this discussion by developing the concept of systemic deficiency in the rule of law.