UPDATE: Here’s the exact quote: “The [House] Oversight Committee has learned that over the objections of the National Archives, you exempted the Office of the Vice President from the presidential executive order that establishes a uniform, government-wide system for safeguarding classified national security information. … The National Archives has informed the Committee that your office intervened to block the inspection. According to a letter that the National Archives sent to your staff in June 2006, you asserted that the Office of the Vice President is not an ‘entity within the executive branch’ and hence is not subject to presidential executive orders.”
UPDATE 2: Here’s the letter from the National Archives to Cheney’s office, which the Oversight Committee (specifically, chairman Henry Waxman) is quoting from. Assuming the director of the National Archives, J. William Leonard, is accurately characterizing the position of Cheney and his aides, it appears their theory is based on the fact that the Office of the Vice President “has both legislative and executive functions.” That’s true, in that the VP is also the President of the Senate, but I think it’s fairly obvious that he’s an executive-branch official with certain legislative functions, not the other way around (which would be unconstitutional anyway), and certainly not neither; he can’t be neither. He’s not his own branch of government, for heaven’s sake.
UPDATE 3: The Democrats respond.