TJ quote...

"The several states composing the United States of America are not united on the principle of unlimited submission to their general government; but by a compact under the style and title of a Constitution for the United States, and of amendments thereto, they constituted a general government for special purposes [and] delegated to that government certain definite powers and whensoever the general government assumes undelegated powers, its acts are unauthoritative, void, and of no force. To this compact each state acceded as a state, and is an integral party, its co-states forming, as to itself, the other party. The government created by this compact was not made the exclusive or final judge of the extent of the powers delegated to itself, since that would have made its discretion, and not the Constitution the measure of its powers."
-- Thomas Jefferson