HispanicBusiness

Presidents dating back to George Washington have claimed a murky power to keep the inner workings of their administrations secret from Congress.

That authority -- known as executive privilege -- isn't in the Constitution. It hasn't been clearly defined by the courts. Yet invoking it has proven effective for presidents determined to keep witnesses or documents away from congressional investigators.

President Barack Obama is the latest to assert the privilege: He refused Wednesday to turn over to a House committee some Justice Department documents.

Some questions and answers about executive privilege:

Q: How can a president shrug off a subpoena from a congressional committee?

A: Presidents say they should be free to engage in private decision-making with their advisers without fearing how their words or internal memos might look to Congress or the public. Several presidents have argued that this authority extends to the work of high-level agency officials, even if they weren't communicating with the president or White House about such work.

Q: Where does the idea of executive privilege come from?

A: It's a principle based on the constitutionally mandated separation of powers -- the idea that the executive branch, Congress and the courts operate independently of each other.

The concept of executive privilege dates at least to 1792, when Congress was probing a disastrous battle against American Indians that cost the lives of hundreds of U.S. soldiers. President George Washington and his Cabinet decided the president had the right to refuse to turn over some documents if disclosing them would harm the public. In the end, Washington gave lawmakers what they sought. But the idea of executive privilege took root.

Q: Didn't the Supreme Court settle the issue when it ordered President Richard Nixon to hand over the Watergate tapes recorded in the White House?

A: Not really. The court ordered Nixon to surrender the tapes in that case -- a criminal investigation. But the justices also found a constitutional basis for claims of executive privilege.

Q: Why not go to court to settle questions about executive privilege once and for all?

A: There's too much risk. Presidents worry that if they lose, courts will take away a valuable tool and weaken the power of the office. If the lawmakers lose, they could permanently weaken Congress' subpoena power when it investigates executive branch blunders.