After years in which the Bush administration has steadily expanded the boundaries of executive power with little or no resistance, some members of the Republican-led Congress - emboldened by the president's low poll numbers or worried about the relevancy of their own institution - have begun to push back.
In the House, leaders of both parties loudly protested the recent FBI search of a congressman's office and have demanded that seized documents be returned. In a rare Senate flare-up, Senate Judiciary Committee Chairman Arlen Specter chided Vice President Dick Cheney last week for interfering in the committee's probe of secret surveillance programs.
The nation's courts have also stepped in. The Supreme Court is expected to rule soon in a case testing the president's use of military tribunals to try terror suspects. In an earlier case, a leading conservative appeals judge said that the administration had risked its credibility when it abruptly changed the venue of one terror case to avoid a possible rebuke by the Supreme Court.
Congressional efforts at righting the power balance can seem self-serving. In an ABC News Poll conducted after the raid of Rep. William J. Jefferson's Capitol Hill office, 86 percent of those surveyed discounted the constitutional claims and said the FBI was in the right. But analysts and legal scholars say the recent skirmishes among the government's three branches follow important historical and political trend lines.
"It's a good start" toward enforcing the separation of powers, said Charles Tiefer, who served as solicitor and deputy general counsel of the House of Representatives and now teaches law at the University of Baltimore. "There have been several periods in the last 30 years when a trend toward an 'imperial presidency' was checked by the congressional branch."
Tiefer pointed to instances of Congress' more fiercely protecting its oversight role after the upheaval of Watergate in the 1970s and the Iran-contra scandal in the 1980s. As in the case of the Capitol Hill office search, he said, the issue that forces realignment often is not glamorous or high-minded: "It occurs when some very real and very flawed human beings come into conflict."
Even as they take up his case, lawmakers in both parties have been at pains to distance themselves from Jefferson, the Louisiana Democrat at the center of a federal bribery investigation. Details of the criminal case, outlined in a lengthy FBI affidavit, suggest the makings of a classic political scandal, with investigators recording Jefferson collecting $100,000 in cash during a clandestine meeting at a Ritz-Carlton hotel, then later finding much of the money in a freezer after a search of his home.
The case has also become a political cause. U.S. District Judge Thomas F. Hogan is scheduled to hear arguments Friday on whether the FBI's search of Jefferson's Washington office was proper or, as the congressman's lawyers and House leaders claim, it violated what is known as the "speech and debate clause" of the Constitution.
That section holds that "for any speech or debate in either House, [members] shall not be questioned in any other place," and is rooted in revolutionary fears about retaliation for unpopular speech. In modern times, the clause has been broadly interpreted to block executive intrusions into the workings of Congress.
"Of course, the Founding Fathers were not so foolish to think that all members would be saints; there would be some who would go astray," Washington lawyer Bruce Fein, an attorney for the Reagan administration, testified at a House Judiciary Committee hearing after the search. But, he said, "There are ample methods under the law and the Constitution that can prove criminal activity of a member without rummaging through their files."
The flap has the administration and Congress in an unfamiliar standoff. On issues such as domestic surveillance, the privacy of presidential papers and the authority to selectively interpret legislation through so-called presidential "signing statements," the administration has faced little opposition as it carved out ever-greater executive authority - in many instances without the consent of Congress and with limited, if any, oversight.
Fein criticized the Bush administration as "bent on a scheme of reducing Congress to something akin to an extra in a Cecil B. DeMille political extravaganza." One legal commentator, George Washington University law professor Jonathan Turley, said he is concerned that the balance of powers in the federal government has become so skewed that it presents "the greatest constitutional crisis of the last century."
"We've had this cult of personality politics for the last two terms, where to support the president is the test for the true believer," Turley said in an interview. He said the broad unwillingness in recent years to challenge the president has drastically reduced Congress' own role - and damaged the White House.
"I think that history will show that the institutional irrelevancy that Congress embraced ... probably hurt the president as much as it hurt Congress," Turley said.
The White House says it wants to work with Congress, but it has also made plain since Bush first took office that it would push aggressively to extend executive powers. In one early clash, the administration refused to release papers from an energy task force headed by Cheney, a decision ultimately supported by the Supreme Court.
After the Sept. 11, 2001, terror attacks and the start of the war in Iraq, the White House extended its push for greater authority, pointing to national security. That echoed assertions of wartime powers by presidents Abraham Lincoln, Woodrow Wilson and Franklin D. Roosevelt, Turley pointed out, but he said that the current administration has faced far less congressional opposition.
Still, there are signs of greater resistance from Congress and from the courts.
In his three-page letter to Cheney last week, Pennsylvania's Specter criticized the vice president for privately urging members of the Senate Judiciary Committee to oppose gathering testimony from telephone company executives about allegations that customer phone records had been collected as part of a classified surveillance program.
"I was surprised, to say the least, that you sought to influence, really determine the action of the committee without calling me first," Specter said in the letter, which also complained about other executive power reaches. "This was especially perplexing since we both attended the Republican Senators Caucus lunch yesterday, and I walked directly in front of you on at least two occasions en route from the buffet to my table."
Without apology, Cheney responded the next day that he was willing to work more closely with lawmakers on oversight of the surveillance programs. "The respectful and candid exchange of views is something to be encouraged, rather than avoided," he said in a letter to Specter.
In coming weeks, the administration could face another check from the Supreme Court. The justices are expected to rule this month on the legal validity of using special military tribunals to try terror suspects being held at Guantanamo Bay, Cuba.
Attorneys for terror suspect Salim Hamdan, a former driver for Osama bin Laden, have criticized the tribunal system as one "unburdened by the laws, Constitution and treaties of the United States." They could get a sympathetic ruling from a court that in a separate terror case two years ago that said that war does not give the president a "blank check" in the legal treatment of suspected enemies.
Last December, another warning shot came from conservative U.S. Circuit Judge J. Michael Luttig. After siding with the administration's position in a terror case concerning the military detention of suspect Jose Padilla, Luttig issued a sharp rebuke when the Justice Department tried to transfer Padilla to civilian court before his appeal could reach the Supreme Court.
But the courts are not just arbiters in the latest power struggles. Some judges are chafing at what they see as an intrusion by lawmakers into what cases come before the nation's courts, and how they are decided. Supreme Court Justice Antonin Scalia, a conservative who opposes the use of foreign law to decide U.S. constitutional issues, nonetheless denounced the notion that Congress should ban the practice. "Let us make our mistakes," he said in a Capitol Hill speech last month, "just as we let you make yours."