Another great student question on Plaut, this time in my e-mail in box.
Question: After initially reading Plaut, I asked the question, "Why is this in the Advisory Opinion section?" I think I realize why now, but wanted to confirm that with you. The following is part of Scalia's opinion in Plaut: "Having achieved finality, however, a judicial decision becomes the last word of the judicial department with regard to a particular case or controversy and Congress may not declare by retroactive legislation that the law applicable to that very case was something other than what the court said it was." This statement appears to me to be grounded in two ideas. First, there is a separation of powers between the Legislative and Judicial branch. More importantly, and directly related to the concept of Justiciability, a process which would allow Congress to alter interpretations of decided Supreme Court cases would abolish all notion of the court's prohibition against advisory opinions and in effect create the possibility that all Supreme Court decision making is subject to further Congressional scrutiny. This doesn't mean that a Congress cannot act to create new laws to avoid a Supreme Court ruling, but they cannot alter laws to re-open final judgments. The authority to pass final judgment on a case is vested in the Supreme Court only . . . and not in Congress. Is this an accurate summary?
Answer: I think that is a terrific summary. On reflection, I think Plaut sits at the confluence of United States v. Klein and Hayburn's Case, and for precisely the reasons you state. It is like Klein in the sense that it involves a fundamental, separation of powers limitation on Congress's ability to regulate the federal courts. Courts adjudicate cases, and Congress cannot interfere with this essential function of the federal judiciary. But it also is like Hayburn's Case in the sense that, were Congress able to unwind final federal court judgments, those "final" judgments would effectively be subject to review by another branch (just as the judicial pronouncements in Hayburn's Case were reviewable by the Executive Branch). In essence, as you say, it would render every judicial ruling, at least potentially, an advisory opinion.