"The creation of crimes after the commission of the fact," Alexander Hamilton wrote, "and the practice of arbitrary imprisonments, have been in all ages, the favorite and most formidable instruments of tyranny." In this passage from Federalist No. 84, Hamilton argues that even without a Bill of Rights—which had not yet been attached—the Constitution nevertheless guarantees what may be the most fundamental political right by preventing the government from imprisoning us without legal justification.
This right traces its origins back to 1215, when the English King John signed the Magna Carta, agreeing that "No Freeman shall be taken or imprisoned, or be disseised of his Freehold, or Liberties, or free Customs, or be outlawed, or exiled, or any other wise destroyed; nor will We not pass upon him, nor condemn him, but by lawful judgment of his Peers, or by the Law of the land." The right is ensured by what is know as the writ of habeas corpus, which requires that authorities either show they have the legal authority to hold a prisoner or let that prisoner go. And it is the right to petition for a such a writ—and not the right to freedom of speech, or of religion, or of assembly—that is guaranteed by the original text of the Constitution. Because if the government can imprison who it wants without any justification at all, those other rights are meaningless.
But in a speech on national security in May President Obama—himself a former professor of constitutional law—proposed giving the government the explicit authority to "preventively detain" people who cannot be convicted of a crime but whom the government believes might nevertheless pose a danger to the country. We have of course already been detaining people without charging them with any crimes, most notably at Guantanamo Bay. The facilities at Guantanamo were explicitly set up with the idea that constitutional protections might not apply at outside the actual territory of the United States. But there has never been any legal authority of the kind Obama proposes for detaining prisoners without charging them, and in Hamdi v. Rumsfeld the Supreme Court has already ruled that the executive branch cannot hold a U.S. citizen indefinitely without judicial review.
Obama, of course, has pledged to close the detention facilities at Guantanamo on the grounds that their existence both undermines the rule of law and gives others a reason to hate us. As part of his plan to close Guantanamo, Obama now intends to move detainees to a supermax prison facility in Thomson, Illinois. But this is at best a symbolic gesture. As I've argued, what we need to do is bring the detainees into our legal system, rather than consign them to an extralegal black hole like Guantanamo. But, as Glenn Greenwald writes, the prisoners moved to the facility in Thomson will not be given jury trials or in some cases charged with any crime at all. Greenwald draws our attention to Deputy Defense Secretary William Lynn's remark that they'll give prisoners trials "only when admissable evidence or potentially available admissable evidence will probably be sufficient to obtain and sustain a conviction." In other words, the prisoners who can show that they are being held without cause won't be given the opportunity to do so. To the extent that this is a legal process, it is a sham. And it may be worse than simply leaving those prisoners at Guantanamo. Instead of looking for a legal loophole which would allow him to detained suspected terrorists indefinitely, as the Bush administration did, Obama wants to write the principle that he can detain prisoners without trial into law. Instead of getting around the constitutional protections against arbitrary detentions in a few cases, he wants to weaken those protections permanently.
There is no doubt that there are people who could not be convicted of a crime but whose freedom could pose a threat to us. Our legal system lets such people go free every day. Indeed, our system is premised on the idea that it is better to let a few potentially dangerous people go than to give the government the power to hold anyone at its own discretion. We give others the benefit of the due process of law—even where we have every reason to believe they may be dangerous—to ensure that we too are allowed our day in court. And while we may be willing to trust Obama with this power, if we give to him, we also give it to the next Nixon, to some future president who treats his own political opponents as enemies of the state.