Justice Kennedy clearly cares about federalism. He has written more than a few opinions extolling the importance of “dual sovereignty” and maintaining judicially enforceable limits on the scope of federal power. Every so often, however, there comes a case in which Justice Kennedy fully and silently joins a majority opinion that embraces an incredibly expansive notion of the scope of federal power. Gonzales v. Raich was such a case (as I noted here). Yesterday’s decision in United States v. Kebodeaux was another. In each case, other justices on the Court felt the need to explain how the decision to uphold federal power was consistent with their prior pronouncements, but not Kennedy. Thus Justice Scalia penned a concurring opinion in Raich, as did the Chief Justice and Justice Alito in Kebodeaux. Justice Kennedy, however, was silent. Justice Kennedy is under no obligation to explain his vote in every case. But in cases like this, his silence is nonetheless conspicuous insofar as he has joined an opinion that appears to be in tension with other opinions he has written or joined. His silence makes it more difficult to understand how Justice Kennedy sees the constitutional limits on federal power and fuels suspicions that he is more outcome-oriented than motivated by constitutional principle.