Recent theoretical work on democracy beyond the nation-state has drawn attention to the emergence of transnational publics as important sources of democratization under conditions of globalization. In this paper, I argue that although there are empirical and theoretical rationales for tracking the potential for global democratization through these vectors, this approach suffers from two limitations: (a) the transnational publics on which they focus have partial, issue- or group-specific concerns that can influence constituted powers but have limited potential for constituent power; and (b) they reveal little about the relationship between democracy at the national scale and democratization at the supranational scale, which a democratic systems approach should explore. For an alternative source of global democratization, I examine transnational democratic protest movements since 2008 as a new type of transnational democratic public that is simultaneously national and transnational, publics that carry a potential for constituent power at both scales of politics.