The writ of habeas corpus and the right to due process have long been linked together, but their relationship has never been more unsettled or important. Following the September 11, 2001 attacks, the United States detained hundreds of suspected terrorists who later brought legal challenges using the writ. In the first of the landmark Supreme Court cases addressing those detentions, Hamdi v. Rumsfeld, the plurality chiefly relied on the Due Process Clause to explain what procedures a court must follow. Scholars assumed due process would govern the area. Yet in Boumediene v. Bush, the Court did not take the due process path and instead held that the Suspension Clause extended habeas corpus process to noncitizen detainees at Guant ´ anamo Bay. Boumediene correctly grounded the analysis in the Suspension Clause, not the Due Process Clause. The Court held that the Suspension Clause demands a traditional habeas process, simply asking whether the detention is legally and factually authorized. This view challenges the set of standards that judges currently use in executive detention cases and also has implications for domestic habeas; it could ground innocence claims in the Suspension Clause. More broadly, this Suspension Clause theory reflects commonalities in the structure of statutes and case law regulating habeas corpus across its array of applications to executive detention and postconviction review. Habeas review now plays a far more central role in the complex regulation of detention than scholars predicted, because habeas review does not depend on underlying due process rights. A judge instead focuses on whether a detention is authorized. As a result, habeas review can inversely play its most crucial role when prior process is inadequate. Put simply, the Suspension Clause can ensure that habeas corpus begins where due process ends.
Brandon L. Garrett, Habeas Corpus and Due Process, 98 Cornell Law Review 47-126 (2012)