WASHINGTON — One day last week, the entire Federal Communications Commission was summoned for the first time in three years before a House committee, where its members were grilled for five hours and told to expect to be "frequent guests."
On another day, Congress authorized subpoenas for Justice Department officials in its escalating investigation into the murky reasons offered by the Bush administration for its decision to fire eight U.S. attorneys.
And on yet another day, former covert CIA operative Valerie Plame was the star witness at a hearing where she accused White House officials of "recklessly" blowing her cover and destroying her career.
Less than three months since they took control of Capitol Hill, Democrats in both chambers have cranked the powerful congressional oversight machinery into overdrive.
In addition to the headline-hogging investigations, Democrats have launched probes into a wide range of less glamorous subjects, including the FDA's efforts to protect the food supply, the way federal agencies monitor energy markets and whether the White House sought to muzzle federal climate scientists who uncovered evidence of global warming.
When Democrats won both houses of Congress in November, they promised vigorous oversight in addition to an ambitious legislative agenda. So far, they appear to be accomplishing more through oversight. None of the bills that were part of the party's 100-hour spree has yet emerged from Congress. And with their razor-thin margin in the Senate, Democrats cannot count on passing any legislation that most Republicans oppose.
But Republicans can do little to stop the investigative juggernaut.
"The Democrats' most powerful weapons aren't legislative bills, but subpoenas and hearings," said John J. Pitney Jr., a former Republican staffer who is a professor of politics at Claremont McKenna College.
Rep. Henry A. Waxman (D-Los Angeles), chairman of the House Oversight and Government Reform Committee, neatly illustrated this dynamic in a recent letter to Secretary of State Condoleezza Rice.
He wrote to ask why President Bush in his 2003 State of the Union address had cited a discredited claim that Iraq was seeking uranium. Waxman noted that Rice had ignored all but five of the 16 letters he had sent over the last five years when his party was in the minority. Then, he pointed out: "I am renewing my request as the chairman of the chief oversight committee in the U.S. House of Representatives."
In that one sentence, Waxman captured one of the most significant changes on Capitol Hill. Now that they have the gavels and subpoena power, the Democrats can no longer be so easily brushed off.
The administration learned that in recent days as Democratic investigations into the firing of U.S. attorneys have shaken the Justice Department. The department has turned over to the House and Senate Judiciary committees scores of e-mails that show some officials misinformed Congress about how the dismissals were handled and raise questions about whether the dismissals were orchestrated by the White House for political reasons.
Democrats on the judiciary committees have threatened to subpoena top White House officials, including Karl Rove, the president's primary political strategist. The chief of staff to Atty. Gen. Alberto R. Gonzales has already resigned. And Democrats -- joined by a few Republicans -- have called on Gonzales to join him.
Rep. Thomas M. Davis III (R-Va.) said the scandal was an example of what happens to an administration unprepared for an aggressive legislative branch. "The problem here is they panicked... and now they got themselves a problem," he said.
Hearings into conditions at Walter Reed Army Medical Center in Washington also have damaged the White House, reinforcing claims that President Bush has mismanaged the Iraq and Afghanistan wars. The hearings confirmed media reports on lengthy treatment delays and deplorable housing conditions for some of the war's most grievously injured soldiers. Both the administration and Congress have pledged more support for wounded soldiers and veterans.
Administration officials now find themselves regularly summoned to explain their actions and policies, something they didn't have to do quite as often when friendly Republicans were in power. The GOP cut the budget of the Government Accountability Office, the investigative arm of Congress, by about a third after it took over in 1994.
Republicans did hold oversight hearings, including some on the tragically slow response to Hurricane Katrina and on the bribery scandal centered on GOP lobbyist Jack Abramoff.
But Davis, the top Republican on the oversight and government reform committee, acknowledged that congressional Republicans, for the most part, were not hard on the administration.
"There is this tendency to think that your political welfare is tied up with the president and you don't want to make him look bad," he said. "This is an administration that has had it pretty easy."