Article 6: This Constitution, and the Laws of the United States which shall be made in Pursuance thereof; and all Treaties made, or which shall be made, under the Authority of the United States, shall be the supreme Law of the Land; and the Judges in every State shall be bound thereby, any Thing in the Constitution or Laws of any state to the Contrary notwithstanding.
And if in recent legislation, what and where?
The Trademark Law Treaty was ratified by the Senate on June 26, 1998, and signed by the president on October 30.
I do not recognize that authority.
Doesn't really matter, if your domain registrar recognizes it. You can sue over the trademark, if you think your lawyers can beat up their lawyers.