Hegel's notion of the cunning of reason in history comes to mind when realizing that the public identification of the Magna Carta at Harvard happened a fortnight or so before the folks in D.C. started asking if any knights might relieve them of this troublesome university.
"The Magna Carta of xxxxxxx" is a trope of American English, perhaps elsewhere as well, standing for the representative document (though usually not in a performative sense, like the Declaration and the Constitution) of a certain hard-won right or liberty. Though its my understanding the Charter of the Forest was the stronger medicine at John's initial concession (subsequently repudiated by Rome).