Valerie Wilson was an active and covert agent of the CIA during the legally relevant period, as every judge who passed judgement on the case early on had to know from classified information. Libby was orchestrating a cover-up of the illegal release of Wilson's identity and Libby kept Cheney fully informed of his activities. Specifically because of Scooter Libby's lies to the FBI and the the Grand Jury it became impossible to prove, legally, that the individuals who actually revealed Wilson's identity had the requisite state of mind (knowledge and intent) that was required to prove a violation of the law. So Scooter's cover-up successfully prevented prosecution of the specific (treasonous) criminals.
Then Fitz takes on the many accusations that Scooter should never has been tried in the first place, let alone convicted.
7. In summary:This trial exposes at least three people who without any level of doubt at all have committed treason to the nation. Those people are I. Lewis "Scooter" Libby, his boss, Richard Cheney, and the innately rotten Karl Rove.
To accept the argument that Mr. Libby’s prosecution is the inappropriate product of an investigation that should have been closed at an early stage, one must accept the proposition that the investigation should have been closed after at least three high-ranking government officials were identified as having disclosed to reporters classified information about covert agent Valerie Wilson, where the account of one of them was directly contradicted by other witnesses, where there was reason to believe that some of the relevant activity may have been coordinated, and where there was an indication from Mr. Libby himself that his disclosures to the press may have been personally sanctioned by the Vice President. To state this claim is to refute it. Peremptorily closing this investigation in the face of the information available at its early stages would have been a dereliction of duty, and would have afforded Mr. Libby and others preferential treatment not accorded to ordinary persons implicated in criminal investigations. [pp. 13-14]
Remember that treason is the only crime that is defined in the U.S. Constitution. It is defined as
Article 3 - The Judicial BranchThose three individuals clearly meet the definition of the crime of treason.
Section 3 - 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. Art 3, Section 3, U.S. Constitution.
I'd also say that anyone attempting to protect them does likewise. Jonas Goldberg from National Review On-line, anyone? Perhaps there should be a list kept on-line of those who are traitors. It could certainly start with Libby, Rove, Cheney and Goldberg.
Here is the Fitzgerald sentencing memo (in .pdf format.)