The Suspension Clause protects liberty by protecting the privilege of the writ of habeas corpus. It provides that the federal government may not suspend this privilege except in extraordinary circumstances: when a rebellion or invasion occurs and the public safety requires it.
Appreciating the significance of this restraint first requires understanding the writ of habeas corpus. This writ, which Americans imported into the Constitution from English common law, is a means by which a prisoner can test the legality of her detention. A person who believes she is being imprisoned illegally can file a petition asking a judge to issue a writ of habeas corpus. When a prisoner files a petition for a writ of habeas corpus, her custodian must explain why the restraint is lawful. If the explanation does not satisfy the court, it will order the custodian to release her. The writ is thus a crucial means by which a prisoner can obtain freedom.
Today, the writ of habeas corpus is primarily used by those serving prison sentences to challenge the legality of the process that resulted in their conviction. Historically, however, the writ was primarily used by those imprisoned without judicial process. Early Americans were keenly aware that monarchs of England had sometimes jailed people indefinitely without charging or trying them in court. Although the writ of habeas corpus existed, the king often ignored it. To protect against such abuse, Parliament enacted the Habeas Corpus Act of 1679 to ensure that the king released prisoners when the law did not justify confining them. This “Great Writ” guaranteed prisoners held on authority of the crown the right to invoke the protection of the judicial process.
The founding generation valued the Great Writ because they had this history in mind. Yet those who framed and ratified the Constitution also believed that in times of crisis, the executive might need leeway to hold suspects without answering to a court. Parliament had suspended the writ during the seventeenth and eighteenth centuries when it concluded that the king needed expanded detention power to contain threats. Similarly, several states had equipped their governors with emergency power by suspending the writ during the Revolutionary War. Pre-ratification practice thus embraced both the importance of the writ and the need for a safety valve.
The Suspension Clause follows in this tradition. It protects the writ by imposing a general bar on its suspension. At the same time, it makes an exception for cases when an invasion or rebellion endangers the public safety. A suspension is temporary, but the power it confers is extraordinary. When a suspension is in effect, the president, typically acting through subordinates, can imprison people indefinitely without any judicial check.
The Clause does not specify which branch of government has the authority to suspend the privilege of the writ, but most agree that only Congress can do it. President Abraham Lincoln provoked controversy by suspending the privilege of his own accord during the Civil War, but Congress largely extinguished challenges to his authority by enacting a statute permitting suspension. On every other occasion, the executive has proceeded only after first securing congressional authorization. The writ of habeas corpus has been suspended four times since the Constitution was ratified: throughout the entire country during the Civil War; in eleven South Carolina counties overrun by the Ku Klux Klan during Reconstruction; in two provinces of the Philippines during a 1905 insurrection; and in Hawaii after the bombing of Pearl Harbor.
The most hotly debated questions concerning the Suspension Clause involve its effect in the absence of a formal suspension.
A threshold question is whether the Clause simply restrains Congress’s ability to suspend whatever habeas jurisdiction is currently on the books, or whether the Clause grants an affirmative right to habeas review (or an adequate substitute for it). On the one hand, the Clause’s general bar on suspension assumes that some access to habeas relief will exist when the privilege of the writ has not been suspended. On the other hand, as Chief Justice Marshall noted in Ex Parte Bollman (1807) the Clause does not itself expressly guarantee that access. The Court seems to have resolved this dispute in Boumediene v. Bush (2008), where it held that the Clause does not simply restrain Congress’s ability to suspend existing habeas statutes but affirmatively guarantees prisoners some forum in which they can challenge the legality of their detention. Also in Boumediene, the Court decided—to much controversy—that habeas jurisdiction extends to prisoners detained outside the United States at Guantanamo Bay.
In recent years, the writ is most commonly sought by convicted defendants in state prison. Each year, over 18,000 petitions for the writ of habeas corpus are filed in federal court by state prisoners against their prison wardens. But a very slim fraction of those petitions are actually successful, in part due to the limits Congress placed on federal courts reviewing habeas petitions when it enacted the Anti-Terrorism and Effective Death Penalty Act of 1996 (AEDPA). AEDPA significantly limited federal courts’ power to grant habeas relief for state prisoners.
The questions about the scope of and limits on the Great Writ are far from settled. Both the Supreme Court’s Guantanamo decisions and AEDPA remain controversial, as we grapple with the Founders’ vision of the writ and the proper balance to strike between liberty and security.