Although the Constitution’s Suspension Clause explicitly mentions the writ of habeas corpus, it does not require that Congress make the writ available in its commonlaw form at all times. Rather, the Clause has long been understood to permit Congress to replace the writ with an alternative procedure, so long as that remedy is an adequate and effective substitute for habeas corpus. Under this functional view of the Suspension Clause, Congress might delegate responsibility for performing the habeas review function to an entity other than an Article III court, so long as the substitute procedure allows a detainee to challenge the lawfulness of his detention fairly and effectively. Because, at its core, habeas is concerned with checking arbitrary executive detention, however, this Article argues that any delegation of the habeas review function to a non– Article III entity must conform to the dictates of the nondelegation doctrine. To delegate the authority for designing the procedures used to challenge executive detention to the very Executive responsible for detention would defeat the purpose of the Clause.

In Boumediene v Bush, the Supreme Court cast doubt on its prior functional jurisprudence regarding the Suspension Clause. In particular, the Court expressed hostility toward any substitute for habeas corpus that did not rely exclusively on an Article III court. This Article criticizes the Court’s approach in Boumediene and demonstrates how it threatens the functional view of the Suspension Clause the Court had embraced previously. At the same time, this Article explains how and why nondelegation concerns justified the result in Boumediene. In particular, by relying so heavily on an executive-designed scheme—the Combatant Status Review Tribunals—Congress’s substitute for habeas delegated excessive authority to the Executive to perform the habeas review function. For that reason, Congress’s attempt to eliminate access to the writ for Guantanamo detainees through the Military Commissions Act of 2006 violated the Suspension Clause when read in conjunction with the nondelegation doctrine. A decision grounded more in nondelegation than in the absolutist conception of the Suspension Clause espoused by the Boumediene majority would have preserved more flexibility for the political branches to design a system for detaining terrorist suspects in the future.