[eno_]

I think you are incorrectly reading this to suggest that this rather weak ability of the government to not be bound by express fuctions gives it the power to strip-mine the "residuary sovereignty" of states and individuals. In fact this very passage explicity puts any additional powers of the fedgov outside of this residuary sovereignty. What they are talking about are relatively tiny scraps of federal power, not the wholesale invention of new powers.

[Roscoe]

I think you are incorrectly reading this to suggest that this rather weak ability of the government to not be bound by express fuctions gives it the power to strip-mine the "residuary sovereignty"

Doesn't sound like thinking to me.