The events that were exposed by Benghazi don’t border on the treasonous - they are way way over that line. Shipping weapons to Al-Qaida while we are at war with them is as strictly treasonous as it gets.
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.