There are two types of the executive privilege. The stronger one is the presidential communications privilege, and the weaker one is the deliberative process privilege.
From Liberty of Law: The Constitution and Executive Privilege
What does Executive privilege protect?
Executive privilege is the constitutional principle that permits the president and high-level executive branch officers to withhold information from Congress, the courts, and ultimately the public. This presidential power is controversial because it is nowhere mentioned in the U.S. Constitution. That fact has led some scholars (Berger 1974; Prakash, 1999) to suggest that executive privilege does not exist and that the congressional power of inquiry is absolute. There is no doubt that presidents and their staffs have secrecy needs and that these decision makers must be able to deliberate in private without fear that every utterance may be made public. But many observers question whether presidents have the right to withhold documents and testimony in the face of congressional investigations or judicial proceedings.advertisement - story continues below
Executive privilege is an implied presidential power that is recognized by the courts, most famously in the U.S. v. Nixon (1974) Supreme Court case. There are generally four areas that an executive branch claim of privilege is based: 1) presidential communications privilege; 2) deliberative process privilege; 3) national security, foreign relations or military affairs, and 4) an ongoing law enforcement investigation. In the current controversy over congressional access to Department of Justice documents pertaining to the Fast & Furious scandal investigation, the president and Attorney General Eric Holder are relying on the deliberative process privilege and also the ongoing law enforcement investigation defense.
In the Fast and Furious scandal, Obama asserted deliberative process privilege, which is the common-law principle that the internal processes of the executive branch of a government are immune from normal disclosure or discovery in civil litigation’s, Freedom of Information Act requests, etc. The issue is now being fought in court, where court precedent is against the Justice Department’s arguments. While the move did buy Obama time, in all likelihood the defense won’t ultimately stand up, granting Congress, and the public, eventual rights to see the documents in question.
If Obama does exert the presidential communications privilege in Benghazi case, the public would never get White House testimony or documents to find out what really happened, in part because the issue is in the realm of foreign policy, an area where courts have held the executive privilege is strong.
But that would require a scandalous allegation by Obama that he participated in the discussions to blame the attack on a YouTube video.
Nakoula Basseley Nakoula, who is also known as Mark Basseley Youssef , was arrested in September 2012 and pleaded guilty to four charges of violating a probation sentence imposed on him in 2010 after a bank fraud conviction, and was sentenced to one year in prison followed by four years of probation. While the subject of the film “Innocence of Muslims” was brought up during the trial, the sentence is unrelated in spite of allegations the film caused the embassy riots. On the contrary, all evidence says otherwise.advertisement - story continues below
Recent developments exposing Deputy National Security Adviser Ben Rhodes’ email to then-U.N. Ambassador Susan Rice instructing her to blame the Benghazi attacks on an anti-Muslim Internet video has raised new questions and put the issue again on the front burner.
Finally, two years after the deaths of Americans at the embassy in Benghazi the House of Representatives will have to act on Speaker John Boehner’s call to form a House Select Committee solely dedicated to investigating the attacks. No doubt Rhodes will be subpoenaed to testify under oath, and all White House emails and documents relevant to this topic will be subpoenaed as well. And whatever names he reveals, those people will be subpoenaed as well.