Nullification is the Jeffersonian idea that the states of the American Union must judge the constitutionality of the acts of their agent, the federal government, since no impartial arbiter between them exists.
The powers of the federal government ... result from the compact to which the states are parties, [and are] limited by the plain sense and intention of the instrument constituting that compact.
[The new Federal Government] would either triumph over the state governments and reduce them to entire subordination or in the course of a few years … the contests about the boundaries of power between the particular [State] governments and the general government … will produce a dissolution of the union.
[In the case of] dangerous exercise of other powers, not granted by the said compact, the states, who are parties thereto, have the right, and are duty bound, to interpose for arresting the progress of the evil.
...the individuals themselves, each in his own personal and sovereign right, entered into a compact with each other to produce a government: and this is the only mode in which governments have a right to arise, and the only principle on which they have a right to exist.
This right to secede is deduced from the nature of the Constitution, which they say is a compact between sovereign States who have preserved their whole sovereignty, and therefore are subject to no superior; that because they made the compact, they can break it when in their opinion it has been departed from by the other States. Fallacious as this course of reasoning is, it enlists State pride, and finds advocates in the honest prejudices of those who have not studied the nature of our government sufficiently to see the radical error on which it rests.
The State or the States.
When any one state in the American union refuses obedience to the Confederation, by which they have bound themselves, the rest have a natural right to compel them to obedience.
When the 13 states were united only by the loose bonds of the Confederation, Jefferson wrote:
There is one view of the subject which ought to have its influence on those who espouse doctrines which strike at the authoritative origin and efficacious operation of the Government of the United States. The Government of the U.S. like all Governments free in their principles, rests on compact; a compact, not between the Government & the parties who formed & live under it; but among the parties themselves, and the strongest of Governments are those in which the compacts were most fairly formed and most faithfully executed.
Every State has a natural right in cases not within the compact (casus non faederis) to nullify of their own authority all assumptions of power by others within their limits. Without this right, they would be under the dominion, absolute and unlimited, of whosoever might exercise this right of judgment for them.
..if the Northern states refuse, willfully and deliberately, to carry into effect that part of the Constitution which respects the restoration of fugitive slaves, and Congress provide no remedy, the South would no longer be bound to observe the compact. A bargain can not be broken on one side, and still bind the other side.
Let me say right here that only unanimous consent of the states can dissolve this Union.
The error is in the assumption that the General Government is a party to the constitutional compact. The States ... formed the compact, acting as sovereign and independent communities.