ABSTRACT
Most of the theories available in the toolbox of European Union (EU) theories start from the assumption that the EU is developing through a process of integration. This chapter firstly presents Brexit as an event that has restored the role of domestic politics in EU theory. It demonstrates the limits of EU theories that focus on a purely rationalist approach of interests. The chapter considers Brexit as an incentive to think more about the de-politicisation/re-politicisation dialectics in the EU. Peter Mair was one of the scholars to make an explicit argument about the relationships between a de-politicisation process in the member states and the very project of European integration. Finally, the chapter shows that Brexit is an incentive to integrate into EU theories new social cleavages that have penetrated domestic politics of the member states politics since the Treaty of Maastricht.
