Privilege: A Primer

What it is: U.S. presidents have said -- and the Supreme Court has agreed -- that they are allowed by the Constitution under certain circumstances to protect the confidentiality of government documents and other information used in making presidential decisions. The idea dates to the earliest days of the republic, and was explicitly affirmed by the court during the Watergate investigation into the Nixon administration. Legal scholars say the bounds of executive privilege remain, in many ways, an unsettled area of constitutional law.

How it works: Presidents have typically invoked executive privilege in response to a subpoena from congressional committees seeking documents as part of an investigation. In response, either chamber of Congress can hold the White House in criminal contempt and call upon a federal prosecutor to issue an indictment.

How often it has been invoked: The term "executive privilege" was coined during the presidency of Dwight D. Eisenhower, who invoked it 40 times. During the investigation of the Watergate break-in, President Richard M. Nixon invoked it to avoid releasing tape recordings of his conversations to an independent counsel. Other presidents have since generally avoided using the term to distance themselves from those events. Ronald Reagan invoked the privilege four times during his presidency, and Bill Clinton used it more than 10 times.

How it has played out: Disputes over executive privilege have usually been resolved before they end up in court. But according to a Congressional Research Service report, Congress has voted executive branch officials in contempt at least eight times.

In the Nixon dispute, the Supreme Court ruled in 1974 that the privilege is constitutional but limited. The court said the privilege belongs only to the president, not his staff, and may be overcome by a demonstration of need, particularly to prove criminal or ethical wrongdoing. The court ordered Nixon to release the tapes.

During the congressional investigation into the Iran-contra affair in 1987, Reagan initially balked when a Senate committee asked for his personal diaries without a formal subpoena. Reagan eventually turned them over to Congress, but legal scholars believe he would have prevailed if the matter had gone to court.

A House committee voted in 1996 to hold Clinton's White House counsel in contempt for refusing to turn over records related to the firings of White House travel office employees. In the end, the counsel surrendered 1,000 pages of documents, hours before the House was slated to vote on the contempt citation.

-- Amy Goldstein and Julie Tate

SOURCES: Congressional Quarterly; "Executive Privilege" by Mark J. Rozell; other legal scholars