Hillary Clinton believed that her husband's affair with Monica Lewinsky was merely a "lapse", dismissing the White House intern as a "narcissistic loony toon", according to newly released private papers from one of her closest friends.
The fresh insight into the mind of Mrs Clinton at the height of the scandal that engulfed her husband's presidency in 1998 came as a new biography on the former secretary of state was published in the United States and momentum continued to build towards a possible presidential run in 2016.
The new papers are the private memos of Diane Blair, a political science professor from Arkansas Mrs Clinton once described as her "closest friend", who was a regular guest at the White House and advised on two Clinton presidential campaigns.
Polls show Mrs Clinton to be the out-and-out frontrunner for the Democratic nomination, but the publication of new documents on the Lewinsky affair show that any presidential campaign will inevitably entail a re-inspection of 35 years of the Clintons' political baggage.
"It was a lapse, but she says to his credit he tried to break it off, tried to pull away, tried to manage someone who was clearly a 'narcissistic loony toon'; but it was beyond control," wrote Mrs Blair in a September 1998 note published yesterday by the conservative Washington Free Beacon webstie.
"HRC [Hillary Rodham Clinton] insists, no matter what people say, it was gross inappropriate behaviour but it was consensual (was not a power relationship) and was not sex within any real meaning (standup, liedown, oral, etc.) of the term."
The note, which recorded a phone conversation with Mrs Clinton, was in a trove of documents given to the University of Arkansas after Mrs Blair's death in 2000, but were only scrutinised and published by the conservative website this week.
The note appears to show Mrs Clinton accepting Mr Clinton's own famously narrow definition of what constituted meaningful sexual contact in his now-infamous denial - "I did not have sexual relations with that woman" - that was given at a highly charged White House press conference.
Although now nearly 20 years ago, Republicans have made clear that the Lewinsky affair - and the Clintons' controversial record in office - is far from forgotten and will resurface if she hits the campaign trail in 2016. Last month Rand Paul, a libertarian Republican senator who is expected to run in 2016, referred directly to the Lewinsky incident to attack both the Clinton brand and challenge the notion that Democrats had a monopoly on the affections of female voters.
Mr Paul accused Mr Clinton of "predatory behaviour" for, as he termed it, "taking advantage of a young girl in his office" - a characterisation of the affair that Mrs Clinton seems to have rejected in her own mind both then and now.
The documents depict Mrs Clinton as "a loyal friend, devoted mother, and a cutthroat strategist" according to the Washington Free Beacon website, a portrait echoed in HRC, a new biography of the former secretary of state that is published today.
The book says that Mrs Clinton's senior aides are already conducting informal interviews to assemble a campaign staff for a 2016 bid, while Mrs Clinton continues to insist publicly that she has not yet decided whether to run for president again.
"This is a campaign that is in full swing," said Jonathan Allen, one of the book's authors. "It's more a question of whether she stops running than whether she starts running."
Mrs Clinton's staff are also strategising about how best to deploy her husband on the campaign trail. While he was a major asset to President Barack Obama's re-election in 2012, he repeatedly courted controversy during her failed attempt to beat Mr Obama in the 2008 primary.
The book also tells of how Mrs Clinton wrote to David Petraeus when he resigned as head of the CIA following an affair with his biographer to express her sympathy and joke "I have a little experience" with infidelity". Mr Petraeus, a decorated former general once talked about as a potential Republican presidential contender, in turn said she would be a "tremendous" president.