It is codified in 18 U.S.C. Sec. 953
Sec. 953. Private correspondence with foreign governments
Any citizen of the United States, wherever he may be, who, without authority of the United States, directly or indirectly commences or carries on any correspondence or intercourse with any foreign government or any officer or agent thereof, with intent to influence the measures or conduct of any foreign government or of any officer or agent thereof, in relation to any disputes or controversies with the United States, or to defeat the measures of the United States, shall be fined under this title or imprisoned not more than three years, or both. This section shall not abridge the right of a citizen to apply, himself or his agent, to any foreign government or the agents thereof for redress of any injury which he may have sustained from such government or any of its agents or subjects.
"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 confession in open court.
"The Congress shall have power to declare the punishment of treason, but no attainderof treason shall work corruption of blood, or forfeiture except during the life of the person attainted."
I would say that the entire television viewing audience constituted witnesses. Ashcroft should set about procuring two horses, two ropes and two strong tree limbs, pronto!