A blog reader who is a close watcher of the Supreme Court sends along the following observations:

At the end of your post on Thomas, you wonder if he was seeking to avoid embarrassing the Chief. I think in that one question you have come close to the answer to most if not all of your (and others’) speculations: this was a compromise decision, with which no Justice, of any stripe, was entirely comfortable, and it was embraced as widely as it was (eight Justices of deeply differing ideological preferences) and was discussed with as little ad hominem rancor as it was (Thomas’ moderation in his critique) because it simply provided a way out of a decisional and institutional corner.
Years from now, when Justices’ papers become available, I strongly suspect that we will discover that the Chief Justice, in the end, simply rode to the rescue of an embattled Court — perhaps not as an act of courage or statesmanship on his part alone, but as the product of a wide (perhaps unanimous) agreement that this was a moment of high institutional risk, and perhaps moral sensitivity, and that the Court was allowing itself to verge very close to a self-inflicted wound. From the very moment the Court encountered this case, it saw it against a sweeping background of history, and realized that much was at stake, on all sides — including the Court’s own potential reputation for causing or contributing to further racial tension.
It thus was OK to vent at oral argument, and get everyone’s subjective perspectives on Section 5’s sweep out into the open. But then a decision had to be written. I would bet that there were attempts by several Justices to shape a decision that would, indeed, strike down Section 5, but the more the drafts circulated, the more monumental the undertaking became. I would not suspect that the Chief Justice then forged, alone, the way out. I would bet that Kennedy and Stevens, and even Scalia, had major roles to play, and perhaps Breyer and Ginsburg, too, but to a lesser extent. Roberts is enough of a craftsman that he would have been entrusted with writing the “final” draft, but it represented a composite of ideas from among the more influential Justices. And, in reading the Roberts opinion closely, one finds that it does, indeed, satisfy all of the internal constituencies within the Court.
I would even conjecture that there was a wider involvement in the Thomas dissent than Thomas alone. He, like Scalia, is entirely capable of excoriating a majority on a point of high principle, as he sees it, but there is absolutely none of that here. I have suspected that the Thomas opinion (comprehensive as it is, especially in comparison to the rather tight opinion of the Court) at one time was the draft opinion for the majority. It was crafted not to give offense, even while declaring Section 5 to be invalid. It was then easy enough to let it become a solitary dissent; and who better to take the responsibility for it, in the United States Reports, than the one African-American on the Court, one who had personally experienced the racial horrors of the past, and who could thus draw vivid comparisons between that era and the present. It also was appropriate for Thomas to be the dissenter because he has acquired (and earned) the reputation of being the one Justice most willing to cast aside the Court’s prior commitments and strike out in bold new directions.
In a phrase, then, I think what went on here was immensely complicated, not yielding to summary assumptions or conjectures.

Extremely perceptive observations, in my view.