The government's position is strongly supported by the former high officials and ex-diplomats, among others. Their attorneys bluntly declared in a brief: "When treaties are at issue, the states disappear and the President and Senate act, in the words of the Supremacy Clause, with the sole 'Authority of the United States.'"
This would imply that, via the Supremacy Clause, the Federal government has the power to “negotiate away” any of our guaranteed rights. Sounds pretty un-American to me…