Constitutional Pluralism Revisited

This essay revisits the theory of constitutional pluralism. This theory was first developed in the EU context as a way of understanding and defending the absence of a broadly agreed source of final authority in the relationship between national and supranational (EU) legal systems and their respective appellate courts in the context of the significant increase in supranational jurisdiction around the time of the Maastricht Treaty 25 years ago. The essay argues that the theory of constitutional pluralism remains relevant today, in particular offering better explanatory and justificatory accounts of the EU than any of the singularist (or monist), holist or federalist alternatives. Its continuing relevance, however, depends on a more explicit focus on the political underpinnings of the legal and judicial dimensions of constitutional pluralism than has typically been the case in the literature, and on more detailed consideration of the preconditions, forms and limits of constitutional initiative in the contemporary phase of unprecedented challenge to the legitimacy of the EU.