Contemporary European public law is marked by the uneasy relationship between national constitutional democracies and the executive-based supranational governance of the European Union. Whereas constitutional democracy remains the dominant source of inspiration for European institutional imagination, the supranational executive has relentlessly expanded its scope and institutional culture to key policy fields at the core of national constitutional democracies. This article tracks the rise of the supranational executive by examining three relational paradigms developed between national constitutional democracies and the European Union in distinct phases of the European integration process (i.e., the complementarity paradigm in the foundational period; the competition paradigm in the transformative period; and the encroachment paradigm during the economic and financial crisis). Following this account, this article claims that the supranational executive, owing to its predominance and ethos, corrodes and gradually displaces national constitutional democracies, bestowing an increasingly post-political character to European public law. This article concludes by discussing the possibilities to reverse the current institutional trend and to realign Europe’s institutional reality and constitutional imagination.