Although, as compared with a state government, the federal government is one of limited and enumerated powers rather than of general powers, it does not follow that it is in any way inferior or subordinate to a state government. On the other hand, its very nature and the purpose for which it was created indicate that in the exercise of the powers granted either expressly or by implication, it must be supreme. In Article VI (¶ 2 ) of the federal constitution, it is declared: "This constitution, and the laws of the United States which shall be made in pursuance thereof, and all treaties made or which shall be made under the authority of the United States, shall be the supreme law of the land; and the judges in every state shall be bound thereby, anything in the constitution or laws of any state to the contrary notwithstanding." In expounding this provision it has been said: "If any one proposition could command the universal assent of mankind, we might expect it would be this: that the government of the Union, though limited in its powers, is supreme within its sphere of action. This would seem to result necessarily from its nature. It is a government of all; its powers are delegated by all; it represents all, and acts for all. Though any one state may be willing to control its operations, no state is willing to allow others to control it. The nation, on those subjects on which it can act, must necessarily bind its component parts" (Marshall, Ch. J., in McCulloch v. Maryland, 4 Wheaton, 316,405). Moreover, in order that the supremacy of the federal government as to those matters entrusted to its authority shall be maintained without encroachment, it is essential that the final interpretation of the extent of its powers shall rest with it alone; and one of the functions of the federal judiciary is to determine ultimately the construction of the federal constitution with reference to the powers of the federal government. Other courts may be called upon in cases properly before them to construe the federal constitution as a part of the written law; but when such constitution has been interpreted in any respect by the supreme court of the United States, that interpretation becomes a part of the supreme law, binding on all the state courts, and on the citizens of the states. (See below, §§ 142,146.)

A clear understanding of the declared supremacy of the power of the federal government, and of the conclusiveness of the interpretation by the supreme court of the United States of the scope of these powers, will indicate that there is no possibility of any conflict between the federal government and the government of a state. If conflicting assertions of authority are to be reconciled by peaceful and lawful means, rather than by the resort to violence, it must be by the recognition of ultimate authority somewhere to determine the controversy; and there can be no reasonable question as to the intention of the framers of the constitution that this ultimate solution should be furnished by the federal government, and that it should be binding upon all.