Everything is ambiguous to the postmodern mind. The real problem is not the structure of the supremacy clause, as pointed out here by a competent legal analyst:
http://mikenew.com/treaties.html
As for your articles, it cannot be disputed that environmental treaties have been abused to undermine Constitutional protections, though as pox has pointed out there are remedies for this and the time is right to pursue them.
And your historical author makes many other worthwhile points. But the theory that some of our founders were in effect traitors, because they included the specific wording about treaties to intentionally frustrate the rights of the people protected in the remainder of the document, is an outrageous theory which is insupportable at best and certainly has not been helped by supreme court precedent, which still, on the whole, uses rational principles of statutory interpretation, which lead irresistibly to the premise that no single clause of the Constitution can ever be understood as abrogating all the rest, especially so because the grammar of the clause more easily supports treaties as subordinate to the Constitution anyway.
Please, I know Mike New. He is no more a "competent authority" than I am.
But the theory that some of our founders were in effect traitors, because they included the specific wording about treaties to intentionally frustrate the rights of the people protected in the remainder of the document, is an outrageous theory,
Nonsense. You cannot interpret Hamilton's choice of language as anything other than deliberate obfuscation.
After the Revolutionary War, the United States was broke. We needed to raise money; else we were sitting ducks for reconquest. The lenders (particularly the French) had terms for loans they would not make with the US under the Articles of Confederation. In that respect, the Constitution contains a checklist: We needed a uniform currency backed by gold. We needed a guarantee that any treaty agreements would be kept as negotiated. We needed national taxing authority. We needed a government capable of securing those loans by means of centralized authority. The Federal government was the answer to those demands. Those who negotiated the terms, including Hamilton, were probably doing so out of what they considered to be patriotism. What was arguably treasonous was that they never disclosed to the people the motive for the obvious snow job and TOTAL ABSENCE of debate on the treaty power during the Federal Convention, which I am certain would have blown the deal. Hence Henry's objection. Hence too, they did what they thought was "the right thing to do," with the kind of condescension typical of the elitists we see today.
BTW, virtually everything I just wrote was agreed to by a truly competent authority who agreed with the above assessment before I even wrote that article: Wayne Hage.