Via this post by Professor Bainbridge, I happened upon the following passage from a 2004 Jeffrey Rosen article in The New Republic, "Supreme Mistake" (11/8/2004):
The willingness of liberal justices to consult international norms in constitutional cases has become a rallying cry for social conservatives: Bork's most recent book is called Coercing Virtue: The Worldwide Rule of Judges. But, although Bork's book is a slapdash polemic, other, more thoughtful conservative scholars, such as Jack Goldsmith of Harvard Law School, have argued persuasively that too much attention to international law could thwart U.S. constitutional traditions and reignite a domestic culture war. There are, after all, dramatic legal and cultural differences between European and American views about free expression, privacy, and due process. This means that, if judges become too willing to look to Europe, they may impose values on U.S. legislatures that the American public will be moved to resist. Moreover, there is nothing inherently progressive about European views on these contested issues: If U.S. courts looked to Europe in abortion cases, for example, they would allow more restrictions than Americans now tolerate.
Breyer and Ginsburg have been appropriately cautious in invoking international norms, citing them only as additional evidence of a consensus in cases where a clear majority of states have also rejected a controversial practice, such as sodomy laws or the juvenile death penalty. But it's possible that younger justices of a more internationalist bent might be more aggressive about invoking a purported international consensus to strike down practices that a majority of the American public continues to support--such as the death penalty for adults. For example, Dean Harold Koh of Yale Law School, mentioned as a possible Kerry Supreme Court nominee, has supported the idea that U.S. courts should expansively apply international legal precedents without the authorization of the president and Congress. And some justices have begun to invoke international law in areas where there is intense social disagreement, such as affirmative action. If anything could reignite the culture wars, it would be a decision by the U.S. Supreme Court to thwart deeply felt currents in American public opinion in the name of the international community. Given Kerry's emphasis on international opinion in his campaign, there's no reason to expect him to be attuned to this danger.