In a notice dated Wednesday, the Justice Department listed 196 pending habeas cases, some of which cover groups of detainees. The new Military Commissions Act (MCA), it said, provides that "no court, justice, or judge" can consider those petitions or other actions related to treatment or imprisonment filed by anyone designated as an enemy combatant, now or in the future.

The relevant section from Section 9 of Article 1 of the Constitution:

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.

Court Told It Lacks Power in Detainee Cases - washingtonpost.com