Parental Rights and Treaty Law
The Supreme Court's current interpretation of the federal government's treaty power poses a threat to parental rights. Essentially, while nothing in the Constitution grants to the federal government any authority to limit parental rights or enact family law in the states, it is currently held that a properly ratified treaty could be executed to grant that power to the federal government in the future.
In its 1957 Reid v. Covert decision, the Court held that "To the extent that the United States can validly make treaties, the people and the States have delegated their power to the National Government and the Tenth Amendment is no barrier."
This means that the Tenth Amendment's reservation of family law authority "to the States respectively, or to the people," is insufficient protection in the event that a treaty is ratified that would give that authority to the federal government.
This current interpretation of the treaty power, which would leave traditional parental rights susceptible to federal overreach through the adoption of such proposed treaties as the Convention on the Rights of the Child or the Convention on the Rights of Persons with Disabilities, is based on the 1920 decision, Missouri v. Holland. In addition, it was recently revisited by some members of the Supreme Court in 2014's Bond v. United States.