Ratification of the Constitution by the State of Virginia; June 26, 1788

We, the delegates of the people of Virginia (…) do declare and make known, that the powers granted under the Constitution, being derived from the people of the United States, may be resumed by them, whensoever the same shall be perverted to their injury or oppression, and that every power not granted thereby remains with them, and at their will; that, therefore, no right, of any denomination, can be cancelled, abridged, restrained, or modified, by the Congress, by the Senate or House of Representatives, acting in any capacity, by the President, or any department or officer of the United States, except in those instances in which power is given by the Constitution for those purposes; and that, among other essential rights, the liberty of conscience, and of the press, cannot be cancelled, abridged, restrained, or modified, by any authority of the United States.

Thomas Jefferson, Draft of the Kentucky Resolutions - October 1798

The several States composing the United States of America, are not united on the principle of unlimited submission to their General Government; but that, 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, -- delegated to that government certain definite powers, reserving, each State to itself, the residuary mass of right to their own self-government; and that whenever the General Government assumes undelegated powers, its acts are unauthoritative, void, and of no force; that to this compact each State acceded as a State, and is an integral party, its co-States forming, as to itself, the other party: that 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; but that, as in all other cases of compact among powers having no common judge, each party has an equal right to judge for itself, as well of infractions as of the mode and measure of redress.

In cases of an abuse of the delegated powers, the members of the General Government, being chosen by the people, a change by the people would be the constitutional remedy; but, where powers are assumed which have not been delegated, a nullification of the act is the rightful remedy: that every State has a natural right in cases not within the compact, (casus non foederis,) to nullify of their own authority all assumptions of power by others.

Draft of the Kentucky Resolutions - 1799

That the several states who formed that instrument, being sovereign and independent, have the unquestionable right to judge of its infraction; and, that a nullification, by those sovereignties, of all unauthorized acts done under color of that instrument, is the rightful remedy;

Thomas Jefferson to William Branch Giles, December 26, 1825

I see, as you do, and with the deepest affliction, the rapid strides with which the federal branch of our government is advancing towards the usurpation of all the rights reserved to the States, and the consolidation in itself of all powers, foreign and domestic;

Liberty, State, and Union: The Political Theory of Thomas Jefferson by Luigi Marco Basani

“This Jeffersonian conception is the reverse image of that of Immanuel Kant. For the German thinker, an ethical approach required existing states to grant increasingly wide-ranging powers to a superstructure, the world Republic designed to guarantee peace. The American held that exactly the opposite was true: It is the free individual owner who is the pivotal element of the system, the freeholder who delegates increasingly smaller powers the further one moves away from him, from that which is most visibly before his vigilant and suspicious eyes. It is his careful attitude and his direct participation, and not the concept of shifting sovereignty further and further upwards, that forms the moral guarantee of the system. Consequently, the fewer powers are delegated, the less these powers are diverted away from the individual’s sight, and the greater will be the result in terms of freedom.” page 210. ( )