Madison, and especially Jefferson, went too far: state sovereignty and supremacy are not consistent with the Constitution’s design. But Madison and Jefferson were right that state authorities have the right and duty to resist unconstitutional actions of the national government. Thus, the proper answer is that state government actors are legitimate constitutional interpreters, but not supreme ones. State officials, no less than federal officials, swear an oath to support the Constitution. And the structure of federalism, as we have seen in Chapter 2, makes states and state officials independent checks on the national government. It is therefore not at all outlandish to think that officers and instrumentalities of state governments possess an independent power of faithful constitutional interpretation…. As demonstrated by Virginia’s and Kentucky’s resistance to the Alien and Sedition Acts, that power sometimes can be a valuable check on unconstitutional action by the national government.
But there is an important constitutional limit to this independent state interpretive power — a boundary that Madison defined inconsistently, that Jefferson disregarded entirely, and that (as we shall see) nullification and secession would attempt to breach violently: independent state power to interpret the Constitution does not mean state supremacy over the Constitution. No state, group of states, or state actor within them has the power to interpret the US Constitution in a way that binds the nation as a whole. Just as states are not literally “bound” by the federal government’s interpretations of the document, the federal government cannot be controlled in its actions by the interpretations of the state. The two levels of government operate as checks on each other, just as the several branches of the national government check one another.