Whatever its outcome, the matter of the president and Monica Lewinsky will likely leave an indelible mark on America's politics and culture.
The aftermath could include everything from the weighty, such as changes in the way top government officials are investigated, to the light, such as a further decline in the respect late-night TV comedians accord the nation's capital.
If nothing else, the long, twisting tale of Bill Clinton and the young White House intern has already pushed many residents of official Washington into a sort of shocked self-appraisal. The story has become so strange, and the atmosphere around it so frenzied, that many here wonder how things got this far.
President Clinton may have explaining to do. But so do the media, investigators, Congress, perhaps even the courts.
"I think the whole country is just appalled by all of it," says Thomas Mann, director of government studies at the Brookings Institution here. "The more the public says, 'Please free us from this,' the more the institutional players in Washington feel obliged to press forward."
The direction the Lewinsky matter takes following the President's testimony, which at time of writing hadn't yet occurred, will depend crucially on whether the public is satisfied that he has told the whole truth. His testimony will not end the investigation so much as launch a new phase.
In this phase, special prosecutor Kenneth Starr will submit his report to Congress - a report that will give new meaning to the phrase "hot potato". Whether it holds impeachment proceedings or not, the House will likely hold hearings on the report, though they might well not begin until after the election and drag on through early next year.
Thus the fate of the Clinton presidency is far from settled. But some effects are already clear. Among them: further decline in public confidence in the interlocking institutions that govern the nation.
Washington's bad image
It is not as if Washington was held in high esteem by the country before Mr. Starr began his long, multifaceted investigation of allegations of Clinton administration misdeeds.
To many voters, politicians and Washington reporters rank near phone solicitors on their lists of least-admired people. Washington itself is perceived as a self-referential swamp, a place where residents get caught up in things that matter little to most of the rest of the country.
But it would be hard to find a better strategy for further damaging public confidence in US leaders than the outcome of the Starr probe, says Brookings' Mann.
According to him, the situation now displays a president who at the very least seems prone to recklessness, an independent counsel who by all accounts is very zealous, and a 24-hour media caught in a frenzy of self-righteousness and pursuit of audiences.
"Put those three players together, and you get a dynamic which leads to a real denigration of politics and public life. It's very sad," he says.
Ironically, it is the office of the independent counsel that may first take the heat for this decline in public confidence. The law, which authorizes appointment of powerful prosecutors with wide-ranging powers to probe top government officials, comes up for renewal next year. It will probably be changed substantially, or perhaps not even renewed at all.
Among the possible changes: limits on the time and money available to independent prosecutors, and a less-sensitive "trigger" provision for appointing them in the first place.
Future presidents - as well as future independent counsels - might be less powerful because of reaction against the excesses of the Lewinsky matter.
"There's no doubt that this has weakened the office of the presidency. The totality of what's occurred has reduced the amount of respect for the presidency," says Bruce Altschuler, an expert on public attitudes towards presidents and chairman of the political science department at the State University of New York at Oswego.
Professor Altschuler points out that during Richard Nixon's administration, then-White House correspondent Dan Rather was heavily criticized for a mildly snippy question during a press conference.
The exchange went like this: "Mr. Rather, are you running for anything?" asked President Nixon, in response to an initial query.
"No," said Rather. "Are you?"
Yet today the jokes made about Clinton on late-night television are not suitable for reprinting in a family newspaper. Such a pounding over time could have a profound effect on the role the resident of the Oval Office plays in American life.
"The reservoir of good will surrounding the presidency has eroded," says Altschuler.
Effect on world stage
This lessening of respect can have real world effects. In the wake of the Clinton administration, the nation may be entering a period when Congress regains power that flowed to the executive branch during the "imperial presidency" decades of the 1960s, '70s and '80s.
In the short term, America's foreign adversaries might also be emboldened.
Many foreign-policy officials believe it is no accident that Iraqi leader Saddam Hussein has begun another round of defiance against United Nations sanctions at a time when the Clinton White House may be preoccupied.
After all, the last spate of problems with Saddam peaked in January - the time when the Lewinsky matter first broke into public attention.