The President, also a lawyer by training, is known to respect his wife's legal brain - she was once listed among the top 100 US lawyers - and to take her advice. Aside from his personal attorneys, she is, in fact, the only person who may advise him in full legal confidentiality.
Hillary is widely believed to have persuaded her husband to resist pressure to make a public "confession". One reason would be legal: that this would have gone back on his earlier sworn statement and so exposed him to a perjury charge.
Another reason is said to be personal: in January, within days of the scandal allegations breaking, Mrs Clinton went on two breakfast television talkshows, calmly and definitely protesting her husband's good faith, grabbing the headlines with her talk of "a vast right-wing conspiracy out to get him".
In the months that followed, Mrs Clinton said no more, appearing quietly by her husband's side, the very image of a faithful wife, and fulfilling a series of solo public engagements, including a rally to mark the 150th anniversary of feminism in America at Seneca Falls in New York State last month.
But the weekend before last there was speculation that relations between the Clintons were not what they had been. Although Mrs Clinton accompanied her husband to his star-studded fundraising trip to Long Island, they seemed cool to each other and she did not attend some events with him.
White House watchers also noted that she had no public appearances scheduled for the two weeks before his testimony on his relationship with Monica Lewinsky for independent prosecutor Kenneth Starr.
The presidential public relations machine swung into action almost at once. During his cross-country tour this week, Mr Clinton paid tribute to Hillary in every speech, referring to her current historical and millennium projects.
When he cut short his tour, he nominated Hillary to fulfil the engagements in Milwaukee in his place. His message to the world was clear - this marriage is a political partnership and it is intact.
On Tuesday, Mrs Clinton gave an interview to the main Arkansas paper, the Democrat-Gazette, in the course of which she blaming "anti-Arkansas prejudice" for some of her husband's difficulties.
On Thursday, she was by her husband's side at the memorial service for the Nairobi bomb victims. They left holding hands.Reuse content