Justice [Sonia]Sotomayor said, "Let's talk - you want to talk about the tax power."And I got like a 10-minute run on the tax power. And, boy, was I glad I did because I was able to get across this idea that, yes, this is a narrower ground on which you can affirm it. And I think everybody agrees. I think even the dissenting justices ultimately in the case agreed that, if Congress had expressly called it a tax, it would be indisputably constitutional.

Very quickly the lawyers in the Justice Department pulled together a set of recommendations about how we ought to defend the law as a constitutional matter. And it was the lawyers in the Justice Department who thought that it was important to include the tax power argument as part of it.

The president [Barak Obama] had been asked some questions by George Stephanopoulos on a news show about whether it was a tax. And he had given an answer that you might read as him saying it wasn't a tax. I think what he said was, "It isn't a tax increase on all Americans."

The part that the public sees is the arguments up at the podium and the briefs that we file. But a significant part of the job - in fact, I'd say I spend more of my time on this part of the job, which is deciding what the position of the United States will be in the cases that we're going to be participating in before the court.

People have got to make their best calls in what they think about a case when they're covering it. But I do think the lesson there, and I guess stating the obvious, that oral argument can as often send a false signal as an accurate signal about where the thing is going.

I had a great deal of independence from the president and the White House during the entirety of my five years. And I'm not sure exactly what that is, but our friend, Walter Dellinger, has a theory about it, and I think he's probably right. And the theory starts with the fact that I worked in the White House for a year and a half before coming over to the position of SG. And because of that, when I was nominated, there was some chatter out there that, "Oh. They're putting a political hack in. This has never happened before."

One thing I've experienced and I feel really grateful for now that I'm on my way out is that I felt that the justices gave that back to me. I really did. You know, of course, you can have some sharp exchanges. That's the nature of the thing, and that's fine. But really in the main I felt like the tone from them was, "Yeah. We may not agree with you, but we're going to have a discussion about this." And it did.