Sanctuary Jurisdictions and Federal Immigration Enforcement Afterthe $70 Billion Appropriation: A Review of Federalism, Preemption,and Spending-Power Challenges

Abstract

Sanctuary jurisdictions have remained a major source of disagreement in United States immigration law, particularly over how much cooperation state and local governments should provide to federal immigration authorities. The issue has become more important following the federal government’s 2026 increase in immigration-enforcement funding, which provides nearly $70 billion for enforcement and related activities. This development raises fresh questions about the balance between federal immigration authority and the independence of states and local governments. This review examines the legal position of sanctuary jurisdictions by considering four main areas: federalism, federal preemption, the anti-commandeering doctrine, and Congress’s power to attach conditions to federal funding. It reviews relevant constitutional principles, Supreme Court decisions, federal legislation, and recent litigation involving sanctuary policies. The review finds that the federal government has broad authority to regulate and enforce federal immigration law, but that authority does not automatically allow it to require state and local governments to carry out federal enforcement duties. Similarly, Congress may use federal funding to encourage cooperation, but funding conditions must remain within constitutional limits. The increased enforcement funding may therefore lead to greater pressure and further litigation involving sanctuary jurisdictions. Overall, the review argues that the central legal issue is not whether the federal government can enforce immigration law, but how far it can require state and local governments to participate in that enforcement. The continuing tension between federal immigration power and local autonomy is likely to remain an important constitutional issue