It’s unconstitutional to execute the mentally disabled. The U.S. Supreme Court at oral argument Nov. 29 wrestled with how states may determine who qualifies as mentally disabled (Moore v. Texas, U.S., No. 15-797, argued 11/29/16).

The court’s liberals hammered Texas Solicitor General Scott A. Keller, arguing for the state, over Texas’s application of intellectual disability standards that appeared to incorporate stereotypes.

Justice Anthony M. Kennedy, on whom the court’s decision will likely turn, questioned both Keller and Clifford M. Sloan of Skadden, Arps, Slate, Meagher & Flom LLP, Washington, who represented defendant Bobby Moore.

Though Kennedy played his...