Article VI, paragraph 2 of the Constitution states: "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." (Emphasis added.)
The phrase: "...shall be the supreme Law of the Land", has been interpreted by the Supreme Court to mean that treaties supersede the Constitution itself - that our rights of freedom of speech, religion, assembly, press, right to keep and bear arms, etc. can be changed or even abolished by a treaty.
http://www.newswithviews.com/Burns/albert.htm
See how easy it will be to complete the "remaking" of America once the hemisphere is "united"?