Richard Schragger is another Slate contributor who teaches at UVA law school. He sent in this email in an effort to clarify where you and I differ Jack.
In his post concerning the "living Constitution" Jack takes Dahlia to task for her naiveté – how can a "living constitutionalist" believe that constitutional law-making is anything other than a mixture of constitutional law and constitutional politics (with the latter more dominant than the former)? This explosion of the law/politics divide is too all-encompassing—and it doesn’t give us much traction on the important question—which is: What does the Constitution require? Jack offers an externalist perspective on constitutional change and calls it the "living constitution" -- but what he is offering is a description of how political/historical forces shape courts and other institutions of government – an account that may or may not be accurate but is, in any case, not what lots of opponents of originalism mean when they speak of the "living constitution." Jack’s description also doesn't answer the question of whether the Court is actually engaged in making law. What I think Dahlia cares about (or, more accurately, what I care about) is the Court from an internalist perspective: We think that the Constitution is law, that law has content, and that legal doctrine has to be justified by an actual theory or account of the Constitution, the rights it contains, and how those rights apply through time.