But many do not seek their rights. They may not know about them; they have no right to counsel—or they may find the conditions of detention unbearable. They can be offered the alternative of something something called “voluntary departure.” Under this heading, aliens agree to leave and pay their own way home. The “advantage” is that an alien who accepts it won’t be detained, and remains at least formally qualified to re-enter illegally. In practice, says my colleague Elizabeth Keyes of the University of Baltimore law school, “voluntary departure has been a bad deal” since it first began to be offered. A person who has departed voluntarily may not apply to come back for at least ten years, and may be subject to exclusion when he or she finally can apply.

Voluntary departure, however, is great for the government. Aliens might more easily be persuaded to take it if they can be kept in isolated detention compounds, far from family, community members, and potential counsel—and possibly subject to mistreatment by the jailers.

Jennings, the first case, now poses the question whether the government can hold people awaiting deportation indefinitely, pending hearings. Two Circuits—the Ninth and the Second—have held that aliens are entitled to a bail hearing and to release while their cases or appeals are pending. They based this holding on statutory language—but that is at best (for the aliens’ point of view) unclear; after hearing an argument about the statute, the Court issued an unusual order on December 15 directing the parties to brief the constitutional issue. Can the government hold aliens indefinitely if they are potentially deportable? For that matter, can it hold anyone indefinitely when the person is not charged with a crime?

(Watch the space below for outraged comments that just being unlawfully present in the U.S. is a crime. Two things: (1) It isn’t; and (2) the aliens are awaiting a civil proceeding, not a criminal trial. If they were charged with a crime, they would have a lot more, not fewer, rights—including a right to counsel and often a right to a bail hearing.)

The constitutional issue is made more portentous by the fact that a Republican Congress could decide to pass legislation stripping statutory guarantees above from some or all of the undocumented who fall into the icy hands of Homeland Security. But it can’t repeal the Constitution.

The answer to that question may mean a lot when the tumbrils of the “deportation task force” begin to roll. Immigration law already gives ICE wide powers over people who fall into its maw; will there be an appetite to give it more?

The second question is whether the government can make detention so miserable that aliens will go on their own? That issue is implicated by a case to be heard Wednesday. Ashcroft is actually three cases all arising out of the hasty post-9/11 roundup of “suspicious” seeming aliens in the New York area. These former detainees are suing the high officials—such as former Attorney General John Ashcroft—who oversaw the “hold until cleared” policy. Under this program, aliens who were grabbed (often off the street, for offenses like taking photographs) were held until the FBI satisfied itself they were no threat. Two reports by the Department of Justice itself have established beyond question that the aliens were held under brutal conditions and subjected to discriminatory treatment by officers at the federal detention center. (One, for example, was held in solitary and subject to such harassment that he could not be transferred to the general population because he was “was crying too much.”)