The Supreme Court ducked the issue raised by this case–whether there are constitutional limits on the federal treaty power. I wrote about this case in Slate a while back. The question was whether a woman who tried to kill or harm her husband’s lover with some chemicals could be prosecuted under a federal statute that implemented the Chemical Weapons Convention. The majority doesn’t think that Congress intended the statute to reach ordinary criminal behavior–or won’t assume otherwise unless Congress is clear that it wants to disregard the normal division of police powers between federal government and states.
Justice Scalia (along with Alito and Thomas) think that the statute is clear (and maybe it is), and therefore the constitutional question cannot be avoided. And they think that the U.S. government lacks the authority to enter a (non-self-executing) treaty that regulates matters that fall within a state’s traditional police powers. (A self-executing treaty is presumably valid to the extent that Congress independently possesses the authority to regulate domestically.)
Why not? Because if the treaty power is unlimited, then the United States and Latvia could enter a treaty that requires each country to block people from carrying guns near schools. This is not my example but Scalia’s (no joke; see p. 13).
The United States and Latvia have not in fact negotiated such a treaty. Why not? Could it be that countries do not enter into treaties that regulate internal matters because they have no reason to do so?
Scalia does not identify any real treaty that he thinks the U.S. government entered into in order to evade constitutional limits on its powers. Surely, he doesn’t think that the federal government entered into the Chemical Weapons Convention so that it could prosecute people who attack each other with household chemicals.
The unstated target of the opinion is the international human rights treaty. Those treaties ban all kinds of police-powers-related stuff. The Senate ensured that they were not self-executing, but I suppose that the next time Democrats control the government, they could pass laws that implement them. At least in theory, a Democratic sweep could result in ratification of a human rights treaty that bans the death penalty, and then implementation of it through a federal statute. Not likely to happen anytime in the next few decades if ever, but you can’t fault Scalia for failing to think ahead.