Mutatis mutandis, the federal government cannot be "sovereign" or "supreme" in your usage, as long as there is a Bill of Rights.
Look, we are down to quibbling about the meanings of words here. What I mean by "Sovereign" is the standard poly-sci and historical meaning. Before we rebelled against Britain, George III was the Sovereign, notwithstanding that he shared power with Parliament and his ministers in Commons. In America after the Revolution, the former colonies become States -- their poleis, their populi, Peoples -- were the Sovereign in each place. Reading Main on that point is clear: the People were Sovereign, and the Antifederalists were concerned that a delegation of too much power to the federal government would make it a National Government, and the Sovereign. Hence the reservations of power -- showing where the power came from in the first place -- and the codification of the reservation in the Bill of Rights.