John Hinderaker severely criticizes Justice Ruth Bader Ginsburg's defense of citing foreign law in American court opinions. My old mentor, Paul Mirengoff, echoes the claim and says that Ginsburg's actions (on the Court, presumably, not the speech itself) warrant impeachment.
In response, Jim Lindgren points to a new paper by Stephen Calabrisi and Stephanie Zimdahl on the history of foreign law citation in American Supreme Court opinions. To put it bluntly, it's a tradition that goes back to the early 19th century and not some new invention by liberal demons. So if we're talking about impeaching Ginsburg for citing to it, then we should be engaging in similar condemnation of Justices Joseph Story and Felix Frankfurter, two of the Justices Calabrisi and Zimdahl identify as most likely to have used foreign law in their opinions. This is doubly ironic, because Justice Frankfurter is the modern Godfather of the "judicial restraint" school of judicial interpretation--the very school that Mr. Mirengoff claims to want more of in our court system (of course, Kelo proved that judicial restraint, like all other legal theories popular on the political right, is only a conservative issue when it leads to conservative ends).
Calabrisi and Zimdahl do not explicitly endorse the citation to foreign law. Rather, they say that the case for it's use is strongest in 4th and 8th amendment cases, amendment's whose language includes vague and socially expansive terms like "unreasonable," "cruel," and "unusual." By contrast "citation to foreign law is least justifiable when the Court is asked to determine whether an unenumerated right is deeply rooted in American history and tradition, as was the case in Lawrence [v. Texas], or whether a federal statute violates American federalism rules, as it was asked to do in Printz v. United States."
Calabrisi and Zimdahl are both primarily conservative originalists, hence the importance to them and other fellow travelers of the long-standing tradition of citing to foreign law. To people who think the longevity of a rule of interpretation strongly relates to its merit, this fact should carry much weight. I, however, am not an originalist (see, e.g., here, here, and here), and thus cannot fall depend on the long tradition of foreign law citation to defend the practice. To quote from Justice Oliver Wendell Holmes: "It is revolting to have no better reason for a rule of law than that it was laid down in the time of Henry IV...and the rule simply persists from blind imitation of the past." So what's my perspective on foreign law?
I'd agree with Zimdahl and Calabrisi that foreign law is most applicable in cases where the constitutional text refers to vague and subjective value judgments (such as the 4th and 8th amendments), although I suspect I'd find more use for it in other opinions than either of them do. However, we should remember that the case where (to me at least) the clamor against foreign law citation really took off was Roper v. Simmons--an 8th amendment case. So even if you're more of Calabrisi-type than a Schraub acolyte, it should be somewhat clear that the latest batch of fury is motivated less by legal reasoning and more by partisan point-scoring. I'd probably go further than they would in asserting that in such cases, opinions from other places are crucial to our understanding of the clauses. You can't undertake an analysis of whether or not a punishment is "unusual" or not without at least noting that our country is one of only four that partakes in it--at least, not without distorting the constitutional text beyond recognition.
But back to the specific question. In the majority of situations, I think that considering foreign law is as useful as any other secondary source in crafting an opinion. Sure, a Swiss justice had no role in writing or ratifying the constitution? So what? Neither did nearly any commentator who wrote nearly any secondary source. A law review article can still be useful even if it was written post 1789--and citing one shouldn't be an impeachable offense. To be fair, the Supreme Court might take precisely this route under warrant--not the impeachment part, but the part about not citing to secondary sources. David Barron made this point to much chatter, although I think the jury is still out. But I think such a stance would be counter-productive to the goal of increased judicial accountability--we can't vote judges out, but we can at least expect them to pay attention to the recent scholarly commentary on their work and past work on parallel issues. A sequestered court is an unaccountable court.
Moreover, I think there are a lot of situations where a diversity of perspectives should be at least examined in order to answer a legal question. Calabrisi and Zimdahl say that foreign law is not particularly useful in determining whether or not a given right is "deeply rooted in our nation's traditions," a key standard for determining whether or not it is a fundamental right covered by the 9th amendment. I'd be inclined to agree. But what about whether it is "implicit in the concept of ordered liberty," another crucial 9th amendment test? There, foreign law and opinion (actually, the whole field of philosophy in general), strikes me as quite relevant to the question. And to answer John's objection that citation to foreign law can just as easily lead to the influence of regressive Muslim state's versus progressive European ones, I think the answer is quite simple: there is no "liberty," ordered or otherwise, in these countries' legal system. Hence, their contribution is of little use to us.
In sum, as long as the foreign law is treated as advisory, not binding, I see no problem in seeing what other commentators had to say about the difficult questions that the Supreme Court has to face. Interpretation is a difficult endeavor--rarely is it as cut-and-dry as the armchair pundits would make it out to be. I would be hesitant, to say the least, of depriving the current manifestation of Justices a tool that they've used for hundreds of years to aid their decisions, solely on the ground that we dislike what they're saying now.