The Supreme Court held oral arguments this morning in a case about chemical weapons and the authority of Congress to pass laws effectuating treaty terms. This is a serious case about whether the Court will overrule a nearly 100 year-old precedent recognizing that if a treaty is valid, Congress has the authority to pass laws to implement its requirements. That has been recognized as a separate grant of authority by the Constitution, which explicitly gives Congress the power to "make all laws which shall be necessary and proper for carrying into execution the foregoing powers [like regulating Congress and coining money], and all other powers vested by this Constitution in the government of the United States, or in any department or officer thereof." (You can read the background of the Bond v. U.S. case – the federal prosecution of a scorned wife for using chemical weapons to poison her husband's girlfriend – in our Term preview.)

As reported by SCOTUSBlog, Justices came up with hypotheticals of the dangers of misinterpreting the Constitution in this case – ranging from sabotaging the president's ability to convince foreign nations that America will live up to its treaty commitments to congressional categorization of chocolate Halloween candy as a chemical weapon because it harms dogs. When Justice Scalia's turn came, his nightmare scenario was … marriage equality:

Justice Antonin Scalia even brought into the argument the current controversy over same-sex marriage, suggesting that the government's argument was so sweeping that the U.S. could join in a treaty approving same-sex marriage, and requiring Congress to pass a law making that binding nationally, on all of the states. Verrilli, Scalia suggested, was trying to "drag Congress into areas where it has never been before."

Thank you, Justice Scalia, for finding a way to combine two right-wing obsessions – the twin threats of foreigners and LGBT people – into one scary scenario. Yes, we all know that evil foreigners are just chomping at the bit to impose their alien (read "European") ways on God-fearing Americans by forcing us to accept those flagrantly immoral gays.

Yes, his scenario raises issues of the extent of congressional authority. But so does the chocolate scenario. Of all the hypotheticals he could have come up with to describe a nightmare scenario, he picked marriage equality.