The "facial" vs. "as applied" distinction animates the minimalism of the Roberts Court. You may remember that Chief Justice Roberts gave a speech at Georgetown shortly after his confirmation, saying that what doesn't have to be decided in a case shouldn't be. But, of course, Chief Justice Roberts also said that he would be pursuing a larger number of unanimous outcomes—an aspiration that seemed to run aground in his second term when the court had one of the highest number of 5-4 opinions in decades. But the "facial/as applied" distinction that resurfaced in the Crawford voter-ID decision and that has played prominently also in areas of abortion ( Ayotte; Carhart ) and more recently in the lethal-injection case ( Baze v. Ky ) reveals that some may have dismissed the chief's efforts at achieving unanimity, or at least greater consensus, prematurely.
As the not entirely ideological 6-3 configuration in the Crawford case reveals, pronouncing an Act of Congress or a whole legislative enactment by the states to be unconstitutional on its face is strong medicine, and for that reason, it is especially unlikely to be pursued by any member of the court inclined toward preserving the idea of a more-tamed judicial posture. Justice Stevens may be substantively liberal, but in terms of his understanding of the judicial role, he is a moderate conservative. His dissent in Bush v. Gore, after all, was about keeping the court out of the presidential election. By distinguishing between the facial and as-applied challenge, Justice Stevens satisfies both sides of his personality: He can be conservative in facial outcome by upholding the statute's general contours while preserving and signaling that he would be substantively liberal in application—e.g., in Crawford being relatively quick to find in a later case that a specific election requirement was burdensome. For somewhat different but overlapping reasons, the "facial/as applied" distinction appeals to Justice Kennedy's Hamlet personality, since he can be for and against the statute at the same time—which may sound flippant, but it in fact reflects Justice Kennedy's commitment to particularized justice. See, e.g., his separate opinion in Rapanos (indulging a multifactored analysis of navigable waters under the Clean Water Act) or Parents Involved (similarly indulging the possibility of some uses of race that are not specifically visited upon the student, but might be used to lessen racial stratification by, for example, a siting decision of where to build a new school).
It should be noted that the "facial/as applied" distinction did not begin with Roberts, though it has been more successful under him. Chief Justice Rehnquist sought to use the distinction in the context of his handcrafted doctrine of 11 th Amendment sovereign immunity, but there, he was using it not to sustain legislation, but to strike it down. Consider, for example, Rehnquist's proposed use of the distinction in Tennessee v. Lane . Rehnquist would have found the ADA to be invalid under the 11 th Amendment on the theory that Congress had not legislated in a congruent and proportional way to address unconstitutional state behavior in a sufficiently targeted fashion. Rehnquist was able to reach this conclusion because he conceived of the proper focus to be facial rather than as applied. In other words, Rehnquist in essence told Congress that it could not legislate more broadly than necessary. In doing its legislative work, Congress had to think of the full range of applications of the statute as against the states and not just a particular application. As Professor Vik Amar once astutely pointed out, since Congress could not tell the states that they had a duty to accommodate the disabled in a public hockey rink as well as a state courthouse, the ADA, which had language that could cover both, was facially unconstitutional, even if in Lane it was properly applied to the denial of courthouse access. Note, however, how using the "facial/as applied" distinction in this way stands the general canon of constitutional interpretation that facial challenges are the most difficult to mount on its head. Rehnquist was effectively seeking to use that facial characterization to limit congressional power more easily, not to be more deferential to it.
It is sometimes said that the jurisprudence of John Roberts is a mere continuation of the Rehnquist era. There is some truth to that. But a closer examination of how the two chiefs employ the "facial/as applied" distinction differently—with Roberts setting a narrow compass of judicial activity and Rehnquist pursuing a more aggressive, less deferential judicial role—undermines that assertion.