Cornell law professor Michael C. Dorf comments on last week’s decision by the U.S. Court of Appeals for the D.C. Circuit holding that federal courts could not enforce a congressional subpoena to former White House Counsel Don McGahn because federal courts cannot adjudicate interbranch disputes. Dorf describes some of the major flaws in the court’s reasoning and explains why the ruling is a clear victory for Donald Trump and a loss for the constitutional system.