Huma Abedin Shares Guilt Over Hillary Clinton Losing Presidency: 'Going to Take It to My Grave'

Huma Abedin's upcoming memoir promises to untangle some of the messiest chapters of her personal life, her relationship as an aide and confidante to Hillary Clinton and the hard-to-quantify affect that all had on presidential politics and the trajectory of a nation.

Both/And: A Life in Many Worlds, which will be released Tuesday, addresses the long, drawn-out unraveling of Abedin's marriage to disgraced former congressman Anthony Weiner, how Clinton comforted her close adviser during Weiner's eventually illegal string of sex scandals and Abedin's unwelcome sexual encounter with an unnamed U.S. senator.

In an interview with CBS Sunday Morning's Norah O'Donnell, Abedin also addressed the feelings of guilt she experienced over Clinton's defeat in the 2016 presidential race to Donald Trump.

As an adviser to the candidate, she bears some responsibility for the campaign's successes and failures. But FBI Director James Comey's so-called "October surprise" 11 days before Election Day — which involved Weiner and Abedin — made Abedin the target of many asking who was to blame for the loss at the ballot box.

"I think I'm going to take it to my grave," Abedin told O'Donnell of the guilt in an interview set to air Sunday on CBS to promote her book. "It took me a while to reconcile that it was not all my fault."

On Oct. 28, 2016, Comey upended the race between Clinton and Trump when he wrote in a letter to Congress that the FBI agents looking into Weiner's illicit text messages to a 15-year-old girl had discovered emails that "appear to be pertinent" to a previously closed investigation into the Democratic nominee's private email server.

Although Comey said the FBI "cannot yet assess whether or not this material may be significant" and Weiner and Abedin were separated at the time, the Clinton campaign found itself again contending with the controversy over how Clinton handled her emails.

Her opponent, himself facing a major scandal over the Access Hollywood tape, pounced.

In their book, Shattered: Inside Hillary Clinton's Doomed Campaign, released in April 2017, Jonathan Allen and Amie Parnes wrote that "Huma was a disaster waiting to happen."

"In any other political operation, she would have been cast aside publicly and brutally long before this moment," the authors also said. "Now her detractors' fears were being realized, and the risk could no longer be ignored."

Abedin did feel responsible as the trouble erupted, a source told PEOPLE after Comey's bombshell. "At one point Huma was sobbing that if she cost Hillary the election, she couldn't live with herself," the source said at the time. "It was excruciating."

Two days before the election, the FBI declared there was nothing new in the emails found on Weiner's laptop. Clinton has called the news of Comey's letter "the determining factor" in her defeat.

Abedin's wide-ranging CBS interview will air Sunday, with a previewing airing on the CBS Evening News this Friday.