INTRODUCTION William Rehnquist's tenure on the Supreme Court presents a Sphinx-like riddle for students of the separation of powers: "What animal is that which in the morning goes on four, at noon on two, and in the evening on three feet?" (1) One might well answer: "Rehnquist's separation of powers jurisprudence, as it is a difficult creature to characterize, arguably evolving over time." (2) In adolescence, it appeared an originalist on all fours, (3) in manhood it walked erect, a Byron White functionalist, (4) and in old age ... well, perhaps the Sphinx might just devour one after all! Indeed, it is difficult to identify a principle unifying the late Chief Justice's separation of powers cases.
