  The problem is that here the chain of authorization comes to an end: There isn’t a higher legal norm that authorizes the enactment of the (original) US Constitution. At this point, Kelsen famously argued, one must presuppose the legal validity of the Constitution. At some stage, in every legal system, we get to an authorizing norm that has not been authorized by any other legal norm, and thus it has to be presupposed to be legally valid. The normative content of this presupposition is what Kelsen has called the basic norm. The basic norm is the content of the presupposition of the legal validity of the (first, historical) constitution of the relevant legal system (GT, 110–111).