Assess graduate students' recall of major U.S. Supreme Court decisions addressing separation of powers: identify each case by name, state its controlling holding succinctly (one or two sentences), and indicate the core constitutional principle affected (e.g., judicial review, executive authority, legislative veto, removal power, presidential immunity). Focus on landmark decisions such as Marbury v. Madison, Youngstown Sheet & Tube Co. v. Sawyer, United States v. Nixon, INS v. Chadha, Myers v. United States, Humphrey's Executor, and Morrison v. Olson; limit responses to concise holdings and significance.