Habeas Corpus is a long-standing constitutional and common law principle that requires the entity holding a prisoner to produce that prisoner and to show demonstrate a charge against the individual. It prevents autocratic governments from holding prisoners in secret for as long as they wish. A complaint made against the Bush administration is that they have violated hits principle. They respond that during a time a war the government is granted extraordinary powers in order to protect itself and its citizens. Bush representatives have cited Lincoln's suspension of habeas corpus as a precedent. Habeas corpus has been denied to the prisoner at Guantanamo as well as for those secreted away to prisons abroad in other countries.
The problem with this argument is that Lincoln acted transparently in his actions, seeking and getting approval of Congress for this momentous step. I would argue it was still a mistake; nevertheless, he did seek congressional approval.
The other argument is that we are in a special war, a battle against terrorism. No explanations of what constitutes victory has been delineated, and in fact, the war seemingly has no end. In addition, the administration argues that secrecy is necessary and we just need to trust them. The Founding Fathers are spinning in their graves. This is precisely what they feared: an autocratic power unchecked by oversight.
If we look at the level of violence, we need only to calculate the number of murders annually in this country: around 150,000. That amount of violence greatly exceeds the numbers who died in terrorist attacks against us. Yet no one would propose suspending habeas corpus for criminals.
Democracy is always best served in the bright sunlight of openness. Habeas Corpus helps us do that and prevents the accumulation of power by the few.