Roberts' impatience is understandable: "The majority merely replaces a review system designed by the people's representatives with a set of shapeless procedures to be defined by federal courts at some future date." Ideally, however, the defining will be by Congress, which will be graded by courts.

McCain, co-author of the McCain-Feingold law that abridges the right of free political speech, has referred disparagingly to, as he puts it, "quote 'First Amendment rights.'" Now he dismissively speaks of "so-called, quote 'habeas corpus suits.'" He who wants to reassure constitutionalist conservatives that he understands the importance of limited government should be reminded why the habeas right has long been known as "the great writ of liberty."

No state power is more fearsome than the power to imprison. Hence the habeas right has been at the heart of the centuries-long struggle to constrain governments, a struggle in which the greatest event was the writing of America's Constitution, which limits Congress' power to revoke habeas corpus to periods of rebellion or invasion. Is it, as McCain suggests, indefensible to conclude that Congress exceeded its authority when, with the Military Commissions Act (2006), it withdrew any federal court jurisdiction over the detainees' habeas claims?

As the conservative and libertarian Cato Institute argued in its amicus brief in support of the petitioning detainees, habeas, in the context of U.S. constitutional law, "is a separation of powers principle" involving the judicial and executive branches. The latter cannot be the only judge of its own judgment.

In Marbury v. Madison (1803), which launched and validated judicial supervision of America's democratic government, Chief Justice John Marshall asked: "To what purpose are powers limited, and to what purpose is that limitation committed to writing, if these limits may, at any time, be passed by those intended to be restrained?" Those are pertinent questions for McCain, who aspires to take the presidential oath to defend the Constitution.