This article explains a longstanding problem in federal Indian law. For two centuries, the U.S. Supreme Court has repeatedly acknowledged the retained, inherent sovereignty of American Indian tribes. But more recently, the Court has developed the implicit-divestiture theory to deny tribal governments criminal and civil jurisdiction over non-members, even with respect to activities on tribal lands. Legal scholars have puzzled over this move from a territorial-based definition of tribal sovereignty to a membership-based definition; they have variously explained it as the Court’s abandonment of the foundational principles of Indian law, the product of the Court’s indifference or even racist hostility to Indians, or a simple lack of doctrinal coherence in the Court’s decisions. This article provides a different explanation. The implicit-divestiture cases represent the Court’s effort to address a trilemma among three incompatible objectives: preservation of the traditional territorial-based definition of tribal sovereignty; preservation of tribal governments’ placement outside the federalist structure of the constitutional order; and preservation of fundamental rights. The Court has chosen to resolve the trilemma by redefining tribal sovereignty to deny tribal jurisdiction over non-members. Whether right or wrong, the implicit-divestiture theory is the Court’s good-faith attempt to preserve as much tribal sovereignty as possible without infringing on fundamental rights or forcing tribal governments into the federalist structure.

Michael Doran, Redefining Tribal Sovereignty for the Era of Fundamental Rights, 95 Indiana Law Journal, 87–144 (2020).