The fundamental question in political theory has always been and continues to be: What justifies the existence of public authority? In contrast, the discipline has mostly ignored the possibility of the deliberate dissolution of political orders – and with them of political communities. Thus, the phenomenon of disintegration, as it can be observed in the context of Brexit, constitutes a major challenge. Exits from or the deconstruction of supranational structures of public authority cannot easily be captured with classical categories of political theory because – from a normative point of view – disintegration is not simply integration in the opposite direction. For example, it makes a fundamental difference whether citizens gain individual rights through EU accession or lose them through withdrawal. We cannot assume that the same standards of (democratic) legitimacy apply in both cases. Against this background, I contend that we need to develop a normative theory of disintegration that explains under what conditions it is justifiable to withdraw from a supranational polity. I consider what conceptual and theoretical resources political theory can draw on in this context and argue that the notion of constituent power can make an important contribution.
