Justice Scalia's opinion in Crawford was based squarely on fidelity to the original understanding of the Confrontation Clause.  The "liberal" wing of the Court was fully on board for this, even though they weren't the biggest fans of originalism generally.  As Justice Scalia summarizes in his opinion today:

Crawford sought to bring our application of the Confrontation Clause back to its original meaning, which was to exclude unconfronted statements made by witnesses--i.e., statements that were testimonial. 541 U. S., at 51.

Okay, so far so good ...

We defined testimony as a " 'solemn declaration or affirmation made for the purpose of establishing or proving some fact,' " ibid.--in the context of the Confrontation Clause, a fact "potentially relevant to later criminal prosecution," Davis v. Washington, 547 U. S. 813, 822 (2006).

Whoa!  Does the original understanding of the Confrontation Clause really support that broad a definition of a statement being "testimonial," and therefore of the person who makes it being a "witness"?  Establishing a fact "potentially relevant to later criminal prosecution" sweeps in a huge range of statements.  "Relevant" is a broad and loose designation, and "potentially relevant" is pretty near boundless.  None of the early American cases cited in Davis support such an enormously broad definition.  Indeed, they involve testimony in its narrowest sense of testimony at prior trials or preliminary hearings or taken by deposition.  See pp. 824-825.

In Michigan v. Bryant, the Supreme Court backed off from this enormously broad definition, over Justice Scalia's dissent.  A policeman found a man with a gunshot in his abdomen and asked him what happened.  He said that Bryant shot him.  He died a few hours later.  The Court decided this was not a "testimonial" statement.  Instead of repeating the Davis formulation, Bryant characterized the primary purpose test as "a primary purpose of creating an out-of-court substitute for trial testimony."  That is a huge difference.

Justice Scalia asserted that he would "continue to adhere to the Confrontation Clause that the People adopted, as described in Crawford ...."  But did they really?  Did the people of the United States in 1791 endorse the "potentially relevant to later criminal prosecution" test for deciding who is a "witness" for the purpose of the Confrontation Clause?

The DNA test* that conclusively refutes Justice Scalia's originalist argument, in my view, is the dying declaration rule.  As described in CJLF's brief in Clark, dying declarations were regularly admitted during the founding era after the adoption of confrontation clauses in many state constitutions, and it was decades before defendants even thought to raise confrontation objections to them.  Yet a dying person's statement as to who wounded him is surely "potentially relevant to later criminal prosecution."  From our brief:

Oddly, though, the Crawford opinion treats dying declarations as a loose end, dropped into a footnote and declared to be acceptable, if at all, only on historical grounds and as sui generis rather than establishing principles applicable to other forms of hearsay. See ibid. That characterization is unsupported by authority or analysis. Further, interpreting the Sixth Amendment in a way that requires an "exception" not contained in the text, see ibid., is highly problematic. If the constitutional mandate is subject to unwritten exceptions, why should the historical one be the only one in perpetuity? If we can make exceptions on the basis of history, why can we not make exceptions on the basis of new knowledge of the types of hearsay that are both reliable and necessary? That is, of course, the road back to Roberts. Cf. id., at 62.

Looking more closely at the nineteenth century dying declaration cases, we see that this category of evidence was not seen as an unstated "exception" to the Confrontation Clause at all, but rather as fully consistent with it. An understanding of the Confrontation Clause consistent with these cases is historically more honest, theoretically more sound, and practically less subject to future creation of further nontextual exceptions.

Today Justice Scalia (pp. 3-4) reiterates his position that dying declarations should be treated as a historically based exception to the rule against "testimonial" evidence without an opportunity for cross-examination, rather than defining "testimonial" in a way that accommodates the undeniable admissibility of dying declarations in the founding era.  That is not the original understanding as far as I have been able to determine.

The opinion of the Court does not go as far as I would, but it takes a large step in that direction.  Consistently with the theme of our brief, Justice Alito says at page 7:

But that does not mean that the Confrontation Clause bars every statement that satisfies the "primary purpose" test. We have recognized that the Confrontation Clause does not prohibit the introduction of out-of-court statements that would have been admissible in a criminal case at the time of the founding.

And at page 10:

Neither Crawford nor any of the cases that it has produced has mounted evidence that the adoption of the Confrontation Clause was understood to require the exclusion of evidence that was regularly admitted in criminal cases at the time of the founding.

This is real progress.  To the extent that Crawford and Davis applied a nonoriginalist gloss to Crawford's underlying originalist rule, the gloss has been largely rubbed away by Bryant and Clark.

In his usual uninhibited style, Justice Scalia "protest[s] the Court's shoveling of fresh dirt upon the Sixth Amendment right of confrontation so recently rescued from the grave in Crawford ...."  But that statement assumes the conclusion that the scope of the confrontation right as defined in Davis really is the true scope.  If the Davis definition is excessively expansive, as I believe it is, today's decision is not shoveling on dirt but scraping off barnacles.

Constitutional theory aside, we should also be aware of the importance of today's decision for real victims of real crimes.  For young children, Confrontation Clause objections to their statements are virtually a thing of the past.  "Statements by very young children will rarely, if ever, implicate the Confrontation Clause."  Mandatory abuse reporting statutes are irrelevant to the "testimonial" status of statements made to mandatory reporters.

For anyone other than police officers dealing with abuse victims, it will now be more difficult to suppress their testimony about victims' statements.  "Statements made to someone who is not principally charged with uncovering and prosecuting criminal behavior are significantly less likely to be testimonial than statements given to law enforcement officers."

None of this should blind us to the potential of hearsay to wrongly convict innocent people.  The reliability of out-of-court statements is something that should be seriously considered in making and applying the rules of evidence in trials.  However, Crawford threw out reliability as a criterion for Confrontation Clause analysis, so that provision of the Constitution is no longer useful as a screen for letting in reliable evidence and keeping out unreliable evidence.  We must return to the hearsay rule and its exceptions for that purpose.

* That is my updated substitute for "smoking gun."