On April 21, 2015, the Supreme Court decided Oneok, Inc. v. Learjet. The question in this case is whether the Natural Gas Act preempts state-law antitrust claims which challenge industry practices that directly affect the wholesale natural gas market when those claims are asserted by litigants who purchased gas in retail transactions. -- In an opinion delivered by Justice Breyer, the Court held by a vote of 7-2 that although the Natural Gas Act occupies the field of matters relating to wholesale sales and transportation of natural gas in interstate commerce, the state law antitrust claims in this case may nevertheless proceed and are not preempted. Justice Breyer’s opinion for the Court was joined in full by Justices Kennedy, Ginsburg, Alito, Sotomayor, and Kagan, and by Justice Thomas except as to Part I-A. Justice Thomas filed an opinion concurring in part and concurring in the judgment. Justice Scalia filed a dissenting opinion, which Chief Justice Roberts joined. The judgment of the Ninth Circuit was affirmed. -- To discuss the case, we have Daniel Lyons, who is an Associate Professor of Law at the Boston College Law School.