No blogger I've read is demanding a massive purge of CIA staff.  But I personally think it is important to both make and accept as legitimate a broader critique of Obama's CIA candidates based on chain of command.  

Mel Goodman did this a little bit regarding John Brennan in his Democracy Now! appearance. From the transcript:

"MEL GOODMAN: OK. John Brennan was deputy executive secretary to George Tenet during the worst violations during the CIA period in the run-up to the Iraq war, so he sat there at Tenet's knee when they passed judgment on torture and abuse, on extraordinary renditions, on black sites, on secret prisons. He was part of all of that decision making."

Goodman is right to hold Brennan accountable for decisions made in and by the CIA. Brennan was one of the leaders - as were Steve Kappes and John McLaughlin, both of whom have been floated for the CIA Director position. I don't think we should punish the lower-level officers in the CIA who carried out specific operations - the Kirakous of the intelligence world.  But we do need to ensure that the honchos of the Bush administration's CIA are held accountable for the decisions they made and that they will not now lead Obama's CIA.

To construct this critique, we need to understand the chain of command in the CIA (esp. before the 9/11 commission report and the establishment of the DNI position).  According to espionageinfo.com :

The "director of Central Intelligence (DCI) oversees the four directorates (Administration, Intelligence, Science and Technology, and Operations), as well as numerous other offices."

"Under DCI is the deputy director of Central Intelligence (DDCI), who assists DCI as head of the CIA and of the Intelligence Community. DDCI also exercises the powers of the DCI when the holder of that position is absent or disabled. Within the CIA and the Intelligence Community as a whole, the offices of the DCI and the DDCI are intended to function virtually as a single unit."

The very top. The buck stops with the DCI and the DDCI. In other words, these two guys, both floated as Obama administration CIA Directors, DCI Hayden and DDCI Steve Kappes, are literally in this together.

Continuing from espionageinfo.com:

"By far the largest chain of command within the CIA, however is the one that runs through the offices of the Executive Director (EXDIR) and Deputy Executive Director (D/EXDIR).

The EXDIR oversees five centers that collectively enable the CIA to carry out its mission: the Chief Financial Officer, Chief Information Officer, Global Support, Human Resources, and Security, each of which have numerous subordinate offices and bureaus. Also under the EXDIR aegis are several independent functions, including the Center for the Study of Intelligence, Office of Equal Employment Opportunity, Ombudsman/Alternative Dispute Resolution, and the Executive Secretary. Finally, the Executive Director's office is in the line of authority between DCI/DDCI and the four directorates."

The Wall Street Journal also has a chart that lays out these relationships nicely.  Note this chart is not the same as the current CIA chart which takes into account the various reforms made in 2004 and onward.

The EXDIR's office has authority over Operations. You know, that directorate where particular rendition and interrogation plans are hatched and carried out. And those in charge of Operations are the Deputy Director of Operations and the Associate Deputy Director of Operations. Pertinently, from June 2002 on Kappes was the Associate Deputy Director of Operations (for more on Kappes, please see here).

Considering that John Brennan served as the Deputy Executive Director, his line about not being "involved in the decisionmaking process for any of these controversial policies and actions" is a little