>Article 3.
>Section 3.
Section 3 defines treason and its punishment.
Treason against the United States, shall consist only in levying War against them, or in adhering to their Enemies, giving them Aid and Comfort. No Person shall be convicted of Treason unless on the Testimony of two Witnesses to the same overt Act, or on Confession in open Court.
The Congress shall have Power to declare the Punishment of Treason, but no Attainder of Treason shall work Corruption of Blood, or Forfeiture except during the Life of the Person attainted.
In Federalist No. 43 James Madison wrote regarding the Treason Clause:
As treason may be committed against the United States, the authority of the United States ought to be enabled to punish it. But as new-fangled and artificial treasons have been the great engines by which violent factions, the natural offspring of free government, have usually wreaked their alternate malignity on each other, the convention have, with great judgment, opposed a barrier to this peculiar danger, by inserting a constitutional definition of the crime, fixing the proof necessary for conviction of it, and restraining the Congress, even in punishing it, from extending the consequences of guilt beyond the person of its author.
Based on the above quotation, it was noted by the lawyer William J. Olson in an amicus curiae in the case Hedges v. Obama that the Treason Clause was one of the enumerated powers of the federal government.[18] He also stated that by defining treason in the U.S. Constitution and placing it in Article III "the founders intended the power to be checked by the judiciary, ruling out trials by military commissions. As James Madison noted, the Treason Clause also was designed to limit the power of the federal government to punish its citizens for “adhering to [the] enemies [of the United States by], giving them aid and comfort.”"[18]
en.wikipedia.org/wiki/Article_Three_of_the_United_States_Constitution