This section is from the book "The Constitutional Law Of The United States", by Westel Woodbury Willoughby. Also available from Amazon: Constitutional Law.
The supremacy of a federal treaty over a conflicting state law, with reference to matters not reserved to the States, has not been questioned since the time it was established that a federal statute, enacted within either the concurrent or exclusive constitutional competency of Congress, operates to nullify all inconsistent state legislation. In this respect, as the Constitution expressly declares, treaties and acts of Congress are upon precisely the same footing.
6 For additional declarations by the Supreme Court that treaties are necessarily subordinate to the Constitution, see Ware v. Hylton, 3 Dall. 199; 1 L. ed. 568; United States v. The Peggy, 1 Cr. 103; 2 L ed. 49; Lattimer v. Poteet, 14 Pet. 4; 10 L. ed. 328; Doe v. Braden, 16 How. 635; 14 L. ed. 1090; Thomas v. Gay, 169 U. S. 264; 18 Sup. C t. Rep. 340; 42 L. ed. 740. In the Wong Kim Ark case, the minority point out that the effect of the decision of the majority is to limit the treaty-making power to prevent children of resident aliens becoming citizens of the United States.
Calhoun, in his Discourse on the Constitution and Government of the United States, says: "It [the treaty-making power] is limited by all the provisions of the Constitution which inhibit certain acts from being done by the government, or any of its departments; of which description there are many. It is also limited by such provisions of the Constitution as direct certain acts to be done in a particular way and which prohibit the contrary, of which a striking example is to be found in that which declares that 'no money shall be drawn from the Treasury but in consequence of appropriations to be made by law.' This not only imposes an important restriction on the power, but gives to Congress as the law-making power, and to the House of Representatives as a portion of Congress, the right to withhold appropriations; and, thereby, an important .control over the treaty-making power whenever money is required to carry a treaty into effect; which is usually the case, especially in reference to those of much importance. There still remains another, and more important limitation, but of a more general and indefinite character. It can enter into no stipulation calculated to change the character of the government; or to do that which can only be done by the constitution-making power; or which is inconsistent with the nature and structure of the government." I Works, 203.
In Ware v. Hylton,7 decided in 1796, Justice Chase says: "There can be no limitation on the power of the people of the United States. By their authority the state constitutions we made, and by their authority the Constitution of the United States was established; and they had the power to change or abolish the state constitutions, or to make them yield to the General Government and to Treaties made by their authority. A treaty cannot be the supreme law of the land, that is, of all the United States, if any act of a state legislature can stand in its way. If the constitution of a State (which is the fundamental law of the State, and paramount to its legislature) must give way to a treaty, and fall before it; can it be questioned whether the less power, an act of the state legislature, must not be prostrate? It is the declared will of the people of the United States that every treaty made by the authority of the United States shall be superior to the constitution and laws of any individual State; and their will alone is to decide. If a law of a State contrary to a treaty is not void, but voidable only by a repeal or nullification of a state legislature, this certain consequence follows: that the will of a small part of the United States may control or defeat the will of the whole. The people of America have been pleased to declare, that all treaties made before the establishment of the national Constitution, or laws of any of the States, contrary to a treaty, shall'be disregarded."
In Fairfax v. Hunter,8 Chirac v. Chirac,8 Hauenstein v. Lyn-ham,10 and other cases, the doctrine declared in Ware v. Hylton was approved and applied.
The attempt has been made to detract from the force of Chase's doctrine as declared in Ware v. Hylton, by emphasizing the fact that in that case the treaty in question was one which had been originally entered into under the Confederation, that is, at a time when the States were severally sovereign, and that, therefore, it was a treaty to which the States may be said to have -individually assented. There would not, however, seem to be much force in this, for if, after the adoption of the Constitution, the treaty in question could be considered in any way as still an instrument deriving its validity from the consent of the State, it could have been abrogated by subsequent state action, but this, of course, was expressly denied by the court in Ware v. Hylton. The truth is that the Constitution puts treaties, made and to be made, upon exactly the same footing, and in the later cases which are cited above, the doctrine of Ware v. Hylton is considered as controlling with reference to treaties made after the adoption of the Constitution.
7 3 Dall. 109; 1 L. ed. 568.
8 7 Cr. 603; 3 L. ed. 453.
9 2 Wh. 259; 4 L. ed. 234.
10 100 U. S. 483; 25 L. ed. 628.
It may, then, be considered as established that a treaty entered into by the Federal Government with respect to a matter within the federal jurisdiction is supreme over a conflicting state law. This leads to the question whether, by an exercise of the treaty-making power, the Federal Government may regulate matters within the States which it may not control by act of Congress, and if, in this respect, the treaty-making power is broader than the legislative, in what respects, and to what extent, it is broader.