The EU's profound crisis has drawn into sharp relief the challenges of reconfiguring national democratic processes around regional political communities. Over the same period for which the EU has fractured, however, other regional organizations have intensified integration. These divergent trends raise urgent questions regarding how regional organizations seek to legitimate integration and associated measures to regionalize decision‐making, and how these legitimation processes can be compared across regional organizations. This article focuses not on specifying how regional organizations should legitimate their activities, but instead on explaining how and why legitimation processes have been crafted in particular ways. Drawing on recent contributions in state theory and political geography, as well as political participation and de‐politicisation, the article advances an innovative approach to understanding how regional integration is (de)legitimated by, first, analysing state‐making and regionalism as ongoing and mutually constituted processes, and second, examining the design and function of participatory innovations.