Jeffrey Toobin in The New Yorker:
Since the Middle Ages, habeas corpus—“You should have the body”—has been the principal means in Anglo-American jurisprudence by which prisoners can challenge their incarceration. In habeas-corpus proceedings, the government is required to bring a prisoner—the body—before a judge and provide a legal rationale for his continued imprisonment. The concept was so well established at the time of the founding of the American Republic that the framers of the Constitution allowed suspensions of the right only under narrow circumstances. Article I, Section 9, states, “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.” Such suspensions have been rare in American history. The most recent occasion was in 1871, when President Ulysses S. Grant sent federal troops to South Carolina to stop attacks by the Ku Klux Klan against newly emancipated black citizens. This fall, however, Congress passed, and President Bush signed, a new law banning the four hundred and thirty detainees held at the American naval base at Guantánamo Bay, and other enemy combatants, from filing writs of habeas corpus.