Article I, Section 9, Clause 2:
The Privilege of the Writ of Habeas Corpus shall not be suspended, unless when in Cases of Rebellion or Invasion the public Safety may require it.
This clause is the only place in the Constitution in which the Great Writ is mentioned, a strange fact in the context of the regard with which the right was held at the time the Constitution was written 1 and stranger in the context of the role the right has come to play in the Supreme Court's efforts to constitutionalize federal and state criminal procedure. 2
Only the Federal Government and not the states, it has been held obliquely, is limited by the clause. 3 The issue that has always excited critical attention is the authority in which the clause places the power to determine whether the circumstances warrant suspension of the privilege of the Writ. 4 The clause itself does not specify, and although most of the clauses of § 9 are directed at Congress not all of them are. 5 At the Convention, the first proposal of a suspending authority expressly vested
in the legislature the suspending power, 6 but the author of this proposal did not retain this language when the matter was taken up, 7 the present language then being adopted. 8 Nevertheless, Congress’s power to suspend was assumed in early commentary 9 and stated in dictum by the Court. 10 President Lincoln suspended the privilege on his own motion in the early Civil War period, 11 but this met with such opposition 12 that he sought and received congressional authorization. 13 Three other suspensions were subsequently ordered on the basis of more or less express authorizations from Congress. 14
When suspension operates, what is suspended? In Ex parte Milligan, 15 the Court asserted that the Writ is not suspended but only the privilege, so that the Writ would issue and the issuing court on its return would determine whether the person applying can proceed, thereby passing on the constitutionality of the suspension and whether the petitioner is within the terms of the suspension.
Restrictions on habeas corpus placed in the Antiterrorism and Effective Death Penalty Act of 1996 (AEDPA) and the Illegal Immigration Reform and Immigrant Responsibility Act (IIRIRA) have provided occasion for further analysis of the scope of the Suspension Clause. AEDPA’s restrictions on successive petitions from state prisoners are
well within the compass of an evolving body of principles restraining
abuse of the writ, and hence do not amount to a suspension of the writ within the meaning of the Clause. 16 Interpreting IIRIRA so as to avoid what it viewed as a serious constitutional problem, the Court in another case held that Congress had not evidenced clear intent to eliminate federal court habeas corpus jurisdiction to determine whether the Attorney General retained discretionary authority to waive deportation for a limited category of resident aliens who had entered guilty pleas before IIRIRA repealed the waiver authority. 17
[At] the absolute minimum, the Court wrote,
the Suspension Clause protects the writ as it existed in 1789. At its historical core, the writ of habeas corpus has served as a means of reviewing the legality of Executive detention, and it is in that context that its protections have been strongest. 18