The right of State interposition strikes at the very foundation of the legislative power of Congress. It possesses no effective legislative power, if such right of State interposition exists; because it can pass no law not subject to abrogation. It cannot make laws for the Union, if any part of the Union may pronounce its enactments void and of no effect. Its forms of legislation would be an idle ceremony, if, after all, any one of four-and-twenty States might bid defiance to its authority. Without express provision in the Constitution, therefore, Sir, this whole question is necessarily decided by those provisions which create a legislative power and a judicial power. If these exist in a government intended for the whole, the inevitable consequence is, that the laws of this legislative power and the decisions of this judicial power must be binding on and over the whole. No man can form the conception of a government existing over four-and-twenty States, with a regular legislative and judicial power, and of the existence at the same time of an authority, residing elsewhere, to resist, at pleasure or discretion, the enactments and the decisions of such a government. I maintain, therefore, Sir, that, from the nature of the case, and as an inference wholly unavoidable, the acts of Congress and the decisions of the national courts must be of higher authority than State laws and State decisions. If this be not so, there is, there can be, no general government. But, Mr. President, the Constitution has not left this cardinal point without full and explicit provisions. First, as to the authority of Congress. Having enumerated the specific powers conferred on Congress, the Constitution adds, as a distinct and substantive clause, the following, viz.: "To make all laws which shall be necessary and proper for carrying into execution the foregoing powers, and all other powers vested by this Constitution in the government of the United States, or in any department or officer thereof." If this means anything, it means that Congress may judge of the true extent and just interpretation of the specific powers granted to it, and may judge also of what is necessary and proper for executing those powers. If Congress is to judge of what is necessary for the execution of its powers, it must, of necessity, judge of the extent and interpretation of those powers.