Abstract As is broadly recognized, the realm of administrative power greatly expanded over the course the twentieth century (particularly after 1945). This essay argues that this expansion, along with differential conceptions of legitimacy deeply bound up with it, are crucial to understanding not just the modern administrative state but also the nature of EU governance and the law governing its operation. Despite a dominant paradigm that seeks to understand EU governance in autonomously democratic and constitutional terms, the legitimacy of integration as a whole has remained primarily ‘administrative, not constitutional’. The EU’s normative power, like all power of an ultimately administrative character, finds its legitimacy primarily in legal, technocratic and functional claims. This is not to deny that European integration involves ‘politics’ or has profound ‘constitutional’ implications for its member states or citizens. The ‘administrative, not constitutional’ paradigm is meant only to stress that the ultimate grounding of EU rulemaking, enforcement, and adjudication comes closer to the sort of administrative legitimacy that is mediated through national executives, national courts, and national parliaments to a much greater extent than the dominant paradigm supposes. This is the reality that the ‘administrative, not constitutional’ paradigm on EU law has always sought to emphasize, and it is one that is particularly pertinent to the integration process in times of crisis. It is unsurprising, in these circumstances, that the public law of European integration has continually resorted to mechanisms of nationally mediated legitimacy in order to ‘borrow’ legitimacy from the national level. Unless and until Europeans begin to experience democracy and constitutionalism in supranational terms, the ‘administrative, not constitutional’ paradigm suggests that the EU’s judicial doctrines must be adjusted. The purpose should be to address the persistent disconnect between supranational regulatory power and its robust sources of democratic and constitutional legitimacy on the national level.