Far be it from me to quarrel with the learned historian, but I don't think his representation of Madison is fair or accurate. Jefferson was a radical, no question. Madison and Jefferson were allies, this is true. They did not like or trust Hamilton, and there is evidence they had good reason not to trust him. But while Madison is closely associated with Jefferson, Madison's views were fairly consistent from '1787 all the way to 1830. IMHO. He was no radical, and he did not champion "state sovereignty" over any other form. He advocated his whole life for the system he helped build, which was one of mixed soveriegnty.
Check this out:
Madison's letter to Everett, 1830
You might find this interesting.