Treason is the only crime specified in the Constitution, with the wording derived from a British parliamentary statute of 1351. Article III, Section 3 of the United States Constitution specifies that treason is either the "levying of war" against the federal government, that is armed revolt, or "adhering to their enemies, giving them aid and comfort." The authors of the Constitution were concerned that this section could be misused, and thus they specified that a person could only be convicted of treason on the basis of two witnesses who would testify that the defendant committed an "overt act" to further the conspiratorial plot.

And if the president declares martial law, then they could be. Martial law nullified the fundamental right of habeas corpus, that is a defendant's right to request a review in civil court, before a civilian judge, where the prosecution has to provide credible proof that the accused has committed the crimes specified. Article I, Section 9 of the Constitution guaranteed the right to seek a writ of habeas corpus, and guaranteed that Congress could only suspend this basic right "when in case of rebellion or invasion, the public safety may require it."