The Constitution says ( concerning treason):
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.
Loss of national citizenship is possible only under the following circumstances:
Fraud in the naturalization process. Technically, this is not loss of citizenship but rather a voiding of the purported naturalization and a declaration that the immigrant never was a United States citizen.
Voluntary relinquishment of citizenship. This may be accomplished either through renunciation procedures specially established by the State Department or through other actions that demonstrate desire to give up national citizenship
Section 3 in the 14th amendment prohibits the election or appointment to any federal or state office of any person who had held any of certain offices and then engaged in insurrection, rebellion or treason. However, a two-thirds vote by each House of the Congress can override this limitation. In 1898, the Congress enacted a general removal of Section 3's limitation.
In 1975, Robert E. Lee's citizenship was restored by a joint congressional resolution, retroactive to June 13, 1865. In 1978, pursuant to Section 3, the Congress posthumously removed the service ban from Jefferson Davis.
In short, even people who commit treason still have the basic rights of a citizen in this country and can only be found guilty of treason in a court of law

