The debate over the legitimacy of judicial use of legislative history has significant legal and political ramifications that have long sparked controversy. As additional commentators join this long-running engagement, the focus of the debate necessarily changes. In a previous article, John Manning argued that the use of legislative history violates the constitutional rule barring congressional self-delegation. Jonathan Siegel argues here that judicial reliance on legislative history does not implicate that rule, because a statute\u27s legislative history already exists at the time of the statute\u27s passage, and statutory incorporation of preexisting materials operates as an adoption of those materials, not as a delegation of legislative p...