Abstract: Separation of powers principles find their way into countless United States Supreme Court opinions, providing justifications for a variety of rules--from the nondelegation doctrine to standing. Predictably, they are also found in cases where the Court defines the amount of power the legislative branch should have over the judicial branch and over adjudications as a whole. The Court's decisions detailing Congress's power to control the federal judiciary by stripping jurisdiction and Congress's power to control adjudications through delegations to legislative courts both rely heavily on separation of powers principles. Curiously, however, the rules come out seemingly opposite. On the one hand, the Court holds that separation of powers requires that Congress have wide, perhaps limitless, latitude to assign or withdraw jurisdiction from Article III courts. On the other, the Court holds that separation of powers prohibits Congress from assigning jurisdiction over certain claims to non-Article III courts. This article examines the puzzling divergence of those rules, with a focus on the distinct separation of powers principles the Court uses to justify them. Finding that the principles applied in the two rules are logically inconsistent, this article asks how the Court found itself in such a logical bind.