This Article applies comparative institutional analysis to separation of powers under state constitutions, with a particular focus on the nondelegation doctrine and states' acceptance of Chadha-like restrictions on legislative oversight. The Article begins by contrasting state and federal doctrine and enforcement levels in each of these separation of powers contexts. Most state courts, unlike their federal counterparts, adhere to a strong nondelegation doctrine. In addition, many states accept (de facto if not de jure) even more explicit and sweeping legislative vetoes than the federal system. The Article highlights the contrast of federal and state approaches by identifying their similarity with Federalist and Antifederalist separation of powers principles, respectively. Once the contrast is drawn, the Article develops a descriptive explanation for this divergence in jurisprudential approach. After discussing the pitfalls of common American heritage, textualism, and culture-based approaches to interpreting separation of powers in state constitutionalism, the Article presents institutional analysis as a better explanation for divergences in interpretive approach. Specifically, the Article discusses institutional design in the legislative and executive branches of states, and its interrelationship with faction and capture of the agency decisionmaking process. Attention to institutional design can explain adherence to the nondelegation doctrine in many states, and can also explain the explicit and sweeping presence of legislative vetoes in some states. In addition, attention to institutional design features and their interrelationship with faction in the decisionmaking process can help to shed light on doctrinal nuances of state court approaches to upholding and striking certain delegations, such as delegations to private boards and to federal agencies. Thus, an appreciation of the role of institutional design is a necessary predicate to the development of an independent state theory of separation of powers.