From today's Confrontation Clause case (Giles v. California):

It is not the role of courts to extrapolate from the words of the Sixth Amendment to the values behind it, and then to enforce its guarantees only to the extent they serve (in the courts' views) those underlying values. The Sixth Amendment seeks fairness indeed -- but seeks it through very specific means (one of which is confrontation) that were the trial rights of Englishmen.

This is the same sort of argument we saw in Justice Scalia's dissent in the self-representation case from last week. We'll see tomorrow if D.C. v. Heller will make it three.