I have now listened to the argument twice and read through the transcript, and here are some quick impressions of the advocates:
* Paul Clement, as usual, was superb. In a sense, though, he had an easier hand. From the beginning, the challengers have been considered underdogs; he had the advantage of watching and listening to the justices for an entire hour before stepping to the lectern; and, well, the questioning he faced was decidedly less hostile. Still, a terrific performance--one of many he has turned in.
* The Solicitor General, Don Verrilli, was, in my view, also terrific, if a bit understated by comparison. One has to realize that the role of the Solicitor General is quite different, and he is not nearly as free as a private attorney to reach for rhetorical heights. Further, the weight of expectations in this case no doubt weighed heavily on the Government. Moreover, it had to be a bit deflating to hear such hostile questions from the get-go--particularly from both the Chief Justice and Justice Kennedy. Still, he was always quite measured and gave subtle, sophisticated answers (regardless of whether you agree with them) that put the Government's position in the best light possible. This is particularly evident in reading the transcript, moreso than in my first time listening to the recording. All in all, a terrific piece of advocacy, especially considering the circumstances.
* Michael Carvin, representing the private plaintiffs, is apt to be a bit polarizing. I thought he was certainly effective in places, but he also seemed to wander a bit, straying from those points on which the individual mandate is most vulnerable. It is hard to assess his argument objectively, though, because he was bailed out by some terrifically unstrategic questioning by Justices Breyer and Sotomayor, who seemed to serve up issues for him on a platter. It was precisely the reverse of what happened to the Solicitor General. While the conservative justices, to some degree, dug in hard with effective, hostile questions of Verrilli, the liberal justices' questions to Carvin only seemed to strengthen his arguments--or at least make them more attractive to the center of the Court.
Again, just some quick impressions. And all of this is probably beside the point. I do not think any of us would really want the constitutionality of the ACA--or the scope of Congress's enumerated powers--actually to turn on who happened to argue the respective sides. In cases like this, the oral argument, while revealing to the listener, is hardly ever relevant to the justices' decisions.