Hey Doug,
I imagine you've seen the same claims in the same places I have, namely on various and sundry "left" chat groups. I really don't recall if those who were making this argument presented hard empirical evidence that U.S. trade negotiators raised this threat in Seattle or any time hence. It certainly makes _logical_ sense to me that U.S. trade negotiators would do this -- that way the Clinton Administration ensures continued AFL-CIO loyalty (no matter how miniscule the crumbs) and pushes for more U.S. exports too (especially critical right now given how the yawning U.S. trade deficit could well put pressure on the dollar, which could well cause capital flight from the U.S. stock market, which would definitely spur a huge-ass domestic and global recession). Plus Third World peasants (who stand to lose the most from liberalized trade regime in agro-food sector, from tougher IP standards, etc.) are the one constituency in this whole shell game that Clinton and Co. don't have to give a rat's ass about (unlike AFL-CIO, globally-oriented U.S. capital, nationally-oriented U.S. capital, Third World neo-liberal elites).
But no, I don't have any specific newswire reports announcing that the U.S. was engaged in this kind of tit-for-tat bargaining, and I don't know if others who have advanced this argument have it either. I don't find it surprising that you tried to corner me on this, because I have seen you in other venues express doubt about whether the U.S. could turn well-intentioned global standards to its imperialist advantage.
John Gulick