Senator Kaufman from Delaware asked Judge Sotomayor about the Leegin case which overturned the per se illegality of resale price maintanence.

Senator Kaufman: But what’s the role of the court in using economic theory to interpret acts of Congress?

SOTOMAYOR: Well, you don’t use economic theory to determine the constitutionality of congressional action. That is a different question, I think, than the one that Leegin addressed.

What Leegin addressed was how the court would apply congressional act, the antitrust laws, to a factual question before it. And that’s a different issue, because that doesn’t do with questioning the economic choices of Congress. That goes to whether or not, in reviewing the action of a particular defendant, what view the court is going to apply to that activity.

SOTOMAYOR: In the Leegin case, the court’s decision was, “Look, we have prior case law that says that this type of activity is always anti-competitive,” and the court, in reconsidering that issue in the Leegin case, said, “Well, there’s been enough presented in the courts below to show that maybe it’s not in — some activities anti- competitive. And so we’re not going to subject it to an absolute bar; we’re going to subject it to a review under rule of reason.”

That’s why I said it’s not a question of questioning Congress’ economic choices or the economic theories that underlay its decisions in a legislation. They weren’t striking down the antitrust laws. What the Court was trying to do was it figure out how it would apply that law to particular set of facts before it.