Interesting stuff. Barron's thesis (that Chief Justice Roberts is lending little or no credence to legal theory not written by one of the three branches itself) has implications for the political process and the system itself. He makes the point, worth repeating, that there are only three opinions by which we can judge the Chief Justice's methods of Constitutional interpretation and there might appear to be a pattern that does not in fact exist. Even so, it's an interesting consideration.
Sure, it's logical, at a certain level, to ignore everything but the Constitution, the statutory law itself, and the reported opinions of the Supreme Court. (See, for example, some of the snarkier comments on Barron's article.) Some version of that is the idea that most people seem to come to law school with - some spot on a continuum between "If a judge said it, it's the law. If not, it's irrelevant." or "If Congress said it, the Supreme Court's got no business messing around with it." At some level, it just seems, well, wrong that law professors sitting in their offices blithely writing "law review articles" should have any say at all over how the law develops.
That, of course, is the problem - they don't, strictly speaking, have any say in the development of the law. However, there's a useful analogy of practical law to the academic fields. Assume a law of ambiguous application (I'm going to be predictable and run with Hart's "No vehicles in the park"). There are a few levels at which materials that aren't "legal" in the strictest sense are useful for ascertaining what a law is "supposed" to mean.
- The simplest is legislative intent. In the United States, Congress keeps extensive records of its hearings. If, hypothetically, the record demonstrated that everyone who voted for the bill was of a similar mind as to its prospective application, then it can reasonably be said that that application was the intended one. This is a bit like determining a President's mandate, of course - a smaller majority of those voting for a hotly-contested bill might not be as compelling. If the legislative intent demonstrates that Congress passed this law because they were concerned about car tires tearing up the grass, then it's a bit more difficult to reasonably ticket a cyclist riding on a path.
- At the next level, we have law review articles, written by professors, practitioners, or students. This is essentially a thinking-tank function. The nation's law schools put out a ridiculous amount of scholarship, written by people with various amounts of experience, various viewpoints (though, yes, more often left-leaning), and various levels of sheer ability to reason. These articles are most useful when they are result-driven, because the best articles leaning toward a particular result have to be well-researched and well-edited, presenting a clear and heavily-cited path to that conclusion. While the Justices of the Supreme Court aren't - and shouldn't consider themselves - bound by this body of scholarship, a well-written article is a fantastic way of exploring such a path. No, the Justices shouldn't use articles merely to bolster an opinion - that's an example of the top-down reasoning that Richard Posner discusses in Overcoming Law, and result-driven opinions are too often blind to the strong points of the opposing side. Rather, articles are useful for examining various bottom-up paths (and, yes, as presentations of most of the law on a subject). If Professor Sven Schmuck of Wassamatta University Law School presents a compelling case that tricycles don't fall within the purview of "vehicles" for the purpose of our statute, and he does so considering the body of law reasonably, of course the Justice writing the opinion should consider it. So little is cut and dry in the law - it's foolish not to consider the highest-quality of the scholarly writings.
- Lower and foreign court decisions are valuable because they offer a chance to examine the ways other jurisdictions have handled similar situations. They aren't, and shouldn't be, binding, but they do present a virtual dry run of the implications of a particular decision.
More importantly, though, I think that ignoring non-governmental sources creates a danger of tunnel vision. Judges are, above all, super-academics. Writing an opinion is essentially like writing a thesis. The most valuable part of academia is the dialectic - the discussion created by original research. Extralegal sources present an opportunity to examine the causes, effects, and implications of a particular decision. The law is an art, yes, but it's also a science, and part of science is examination by others. Time will tell if the Chief Justice keeps himself willfully blind to such examination.