The outcome hung on whether Monica Lewinsky, 24, would confess that she had a sexual relationship with Bill Clinton, and that he persuaded her to lie about it, or whether she would deny everything, risking perjury charges and imprisonment to save the President's skin.
As the furies gathered, one woman who had no doubts where she stood was Hillary Clinton who, having publicly declared the allegations against the President to be "absolutely false", has thrown herself full-bloodedly into the fray. Centrally involved in preparing the President's defence - "in the thick of this" according to one White House official - her response to the crisis has been defiant.
She may need all the courage she can muster, for Ms Lewinsky was reported by sources close to the case yesterday morning to be ready to tell all about the alleged affair with the President. But the decision turned on whether her lawyer, William Ginsburg, would succeed in extracting from the special prosecutor investigating Mr Clinton, Kenneth Starr, a guarantee of immunity in exchange for his client's co-operation.
Before beginning negotiations with Mr Starr yesterday, Mr Ginsburg laid down his bottom line. "I would ultimately like to get her a promise of no prosecution and immunity," he said.
That was tantamount to an admission that Ms Lewinsky lied in a sworn affidavit she gave on 7 January to lawyers for Paula Jones, who is pursuing a sexual harassment suit against the President. In the affidavit, Ms Lewinsky categorically denied having sex with the President. Mr Starr is convinced that he has her over a legal barrel because he has 20 hours of secretly recorded tapes where Ms Lewinsky, who met the President in 1995 when she was 21, volunteers graphic details of her White House escapades.
Agents for Mr Starr reportedly searched Ms Lewinsky's apartment, seizing a computer, dark cocktail dress, gold brooch and gifts from a shop on Martha's Vineyard, Massachusetts, where the Clintons holiday. Speculation centred on the cocktail dress, rumoured to have been saved by Ms Lewinsky as a souvenir and to be stained with semen which could be tested for DNA to prove the existence of the affair.
According to the latest leaks over the Lewinsky tapes, she indicated she never had intercourse with the President, only oral sex and phone sex. Ms Lewinsky is also heard saying, according to a source who heard 90 minutes of tape and narrated details to the Los Angeles Times, that the President told her he did not consider oral sex to amount to a fully- fledged affair - which may explain, in a convoluted sort of way, why under interrogation from Ms Jones's lawyers last weekend, Mr Clinton reportedly confessed to an affair with Gennifer Flowers but denied an affair with Ms Lewinsky.
During the 1991 election campaign, Mr Clinton denied Ms Flowers's claims that the two had been lovers for 12 years. Had he told the truth, it is likely he would not have become President.
History turned then on two or three words, and it may again if Ms Lewinsky convincingly reveals she and Mr Clinton had sex of any kind. The strange Clintonian definition of an "improper sexual relationship" or an "affair" will carry little weight if he concedes Ms Lewinsky acceded to the requestPaula Jones says she refused.
Should he attempt to seek refuge in a felicitous interpretation of Old Testament morality, as he has in the past, his departure from the White House would be greeted with more laughter than tears. Two state troopers told the Los Angeles Times in 1993 that Mr Clinton said he consulted the Bible and established that extra- marital oral sex was not adultery.
According to the newspaper's source, Ms Lewinsky "never claims it was intercourse", yet derived such emotional nourishment from the oral and telephonic encounters as to feel the pain of a jilted lover.
"Monica is whining," the source said of the tapes, "...She feels moved out." As might Mr Clinton, very soon, unless Ms Lewinsky will submit to further sacrifices on his behalf.