The DNC's Kicking Ass points to this LA Times article on the intelligence debates on Powell's 2/5/03 speech before the UN. The entire article is worth reading, but this paragraph is the most damning:
The CIA rejected requests for initial versions of what became the Powell presentation on the grounds that they were internal working documents and not finished products. And the Republican-controlled committee did not seek access to a 40-plus-page document that was prepared by Vice President Dick Cheney's office and submitted to State Department speechwriters detailing the case the administration wanted Powell to make.
What grounds are those to refuse to give the documents to the SSCI? The entire point of the investigation was to determine where the intelligence process broke down - how can the CIA declare internal working documents off limits? They are the whole ball game.
The SSCI report has been interpreted as exonerating the Office of the Vice President on the charge that it politicized intelligence. Yet the Committee didn't even ask to see the 40 something page memo sent by Cheney's office? Why was the OVP involved in the process at all - did it haven some unique capacity, other than a willingness to misread raw intelligence, to contribute?