As they trade threats and bluster over whether top White House aides will publicly testify about the firings of federal prosecutors, Congress and the Bush administration seem headed for a constitutional confrontation.
But if history is any guide, it is a showdown that will be settled by political negotiation. Most disputes over executive privilege – the legal doctrine that discussions between a president and his advisers can be kept secret – don't end up as lawsuits, say experts.
"These matters are not traditionally litigated," says Carl Tobias, a law professor at the University of Richmond. "Courts don't like them and it takes too much time."
There are important exceptions to this rule. Near the beginning of President Bush's first term, the administration refused to release to Congress papers from an energy task force headed by Vice President Dick Cheney. That position was ultimately supported by the US Supreme Court.
However, recent presidents – including Bill Clinton and Mr. Bush – in general have used a threat of resorting to a claim of executive privilege as their opening bid in a poker game with Congress over the release of internal information.
Some feel this trivializes an important aspect of the American system of the separation of powers of the branches of government. The invocation of executive privilege should be a last resort, says Mark Rozell, a professor of public policy at George Mason University in Fairfax, Va.
If Bush truly believes that political adviser Karl Rove and other current and former top aides should not give sworn testimony about the firings of US prosecutors, he should not allow them to speak to Congress at all, says Professor Rozell. Yet the administration has already offered to allow aides to speak with lawmakers in private.
"If he's willing to let them talk, why not under oath?" says Rozell. "It seems to me this is also an opening of negotiations by the president."
Still, on Wednesday the confrontation between Congress and the White House became at least one notch more intense. A House Judiciary subcommittee on a voice vote approved the issuance of legal orders for Mr. Rove, former White House counsel Harriet Miers, and others to testify under oath about the dismissals of eight US attorneys.
The Senate Judiciary Committee scheduled a similar vote for Thursday. Democratic lawmakers say the threat of subpoenas seems the only way to get public answers from the White House.
Previously, the White House dispatched counsel Fred Fielding to Capitol Hill with the offer of unsworn private testimony. The administration characterized the offer, combined with the release of 3,000 pages of Justice Department internal communications on the matter, as an unprecedented window into personnel decisionmaking within the executive branch.
Bush signaled he is willing to resort to the courts if Congress turned down the offer. "The president must remain faithful to the fundamental interests of the presidency and the requirements of the constitutional separation of powers," said a letter to congressional leaders from Mr. Fielding.
The phrase "executive privilege" does not appear in the US Constitution. But presidential claims to preserve the confidentiality of information and documents intermittently have been an aspect of relations between Congress and the White House since George Washington's days as president, according to a Congressional Research Service report on the subject.
The point of executive privilege is to ensure that a president receives candid advice from those around him. The fear of being hauled before a congressional committee to disclose their thinking might make aides less likely to speak their minds, goes the legal theory.
The nadir of this legal doctrine may have occurred under President Richard Nixon, who invoked it in an effort to keep from turning over his Watergate tapes. In 1974, the Supreme Court decided against him, setting the stage for the downfall of his presidency.
In the immediate aftermath of the Watergate scandal, presidents invoked the claim weakly or not at all. None wanted to be associated with a phrase discredited by Mr. Nixon.
Mr. Clinton reversed this trend, says Rozell. He exercised the power more often than did his five predecessors combined, in matters such as an attempt to protect information related to the dismissal of employees at the White House travel office.