Jeffrey Toobin thinks so, saying the issue of Koh's purported belief in "transnationalism"--i.e. the belief "that American courts should honor and apply the laws of other nations in our courts"--could derail his nomination to serve as the legal advisor at the State Department. Although the most serious charge in the effort to paint Koh as a transnationalist--the charge that he believes sharia should be applied in U.S. courts--is bogus, that doesn't mean the issue as a whole is a total fabrication. As Toobin writes:
The point is that this issue is politically toxic, and a real danger to Koh’s confirmation, if it’s mishandled. The issue taps into deep feelings of nationalism, mostly but not only among conservatives. Citizens of the European Union countries regard the power of that central authority with great concern, but that’s nothing compared to the skepticism here about the United Nations and other international organizations. It might be easy to assume, given Koh’s manifest qualifications for the job, that he will cruise to confirmation. He still may. But this issue is politically radioactive, and he and his sponsors ought to approach it with great caution.
Something to keep an eye on, although I think conservative legal activists are going to have to choose which Obama legal nominee they really want to go after: Koh or Dawn Johnsen. It seems like there's only so much energy and political capital they can expend on this sort of thing.