Brief Fact Summary. Missouri wanted to prevent US game warden Holland from enforcing Migratory Bird Treaty Act of 1918 (the Treaty). It claimed the Treaty infringed on Missouri’s 10th Amendment right against federal intrusion and that Missouri has a pecuniary interest as owners of the birds within its borders. The District Court dismissed the suit and the state appealed.
Synopsis of Rule of Law. Treaties take precedence over any conflicting state law (regardless of whether the treaty came before or after the enactment of the state law). A federal law can trump an earlier rule in treaty if it is clear that it is meant to do so, or the provisions cannot be fairly reconciled. If the treaty comes later it can trump federal law even if federal law is inconsistent. The last will of the sovereign controls.
Held. Justice Holmes opinion: Yes. District Court judgment affirmed.
The state’s claim of sovereign power over possessions is not stronger than the authority a treaty is granted under the Constitution. The birds are not in the possession of anyone and possession is the beginning of ownership. Under Article 6, treaties, the Constitution, and laws of the US made in pursuance thereof are the supreme laws of the land. If the treaty is valid then there is no dispute about the validity of the statute that is to execute the treaty.
The national interest is keeping migratory birds is high because they are a food supply and also protect forests and corps. The birds are only transitory within Missouri and have no permanent habitat there.
Discussion. What if the US made a treaty with Spain that said it is a crime punishable to publish criticisms of either government? Missouri let Congress bypass the 10th Amendment. Would such a situation allow Congress to bypass the 1st as well? Holmes might say that freedom of speech is specific in the Constitution. Migratory birds do not appear anywhere in the Constitution. Protecting birds would be in the public’s interest whereas restricting freedom of speech would be contrary to that interest.