Joe McCarthy got going.
Rather than deal with him directly, Eisenhower simply greatly expanded the scope of Executive Privilege unilaterally, to protect him as President and his favored folk from McCarthy, and to hell with everyone else.
Yet, Judge Sirica, an Eisenhower appointee, cut into the doctrine greatly when he ordered the Nixon White House to turn over its tapes of conversations Nixon held in the Oval Office.
Holder seeks to expand the claim well beyond any precedent because he has claimed that the Executive was was not involved in any of the communications, yet the claim of Executive Privilege should relieve the administration of any duty to turn over things for which Congress is asking.
http://en.wikipedia.org/wiki/Executive_privilege Remember when Obama promised us the most transparent administration ever?