Presidential Claims of Executive Privilege: History, Law, Practice and Recent Developments [August 21, 2012] [open pdf - 464KB]
"Presidential claims of a right to preserve the confidentiality of information and documents in the face of legislative demands have figured prominently, though intermittently, in executive congressional relations since at least 1792. Few such interbranch disputes over access to information have reached the courts for substantive resolution. The vast majority of these disputes are resolved through political negotiation and accommodation. In fact, it was not until the Watergate-related lawsuits in the 1970s seeking access to President Nixon's tapes that the existence of a presidential confidentiality privilege was judicially established as a necessary derivative of the President's status in our constitutional scheme of separated powers. There have been only four cases involving information access disputes between Congress and the executive, and two of these resulted in decisions on the merits. The Nixon and post-Watergate cases established the broad contours of the presidential communications privilege. […] President Obama formally invoked executive privilege for the first time on June 20, 2012, over documents sought by the House Committee on Oversight and Government Reform in its ongoing investigation into Operation Fast and Furious."
CRS Report for Congress, R42670