"I am done with being a candidate," she affirmed in an interview about the book that aired on CBS Sunday Morning.
In Clinton's memoir, her third, she blasts other Democrats and spells out views that would make her unlikely to lead any future Democratic Party, in a frank manner that runs counter to her reputation as a cautious, calculated politician.
In addition to her biting criticism for her 2016 Democratic rival Bernie Sanders
, she urges Democrats not to shy away from the politics around gun control, pushes them to keep their focus on both the Russia investigation and the economy and stresses the need to learn from her mistakes against Trump.
"Democrats should not respond to my defeat by retreating from our strong commitments on these life-or-death issues," she writes. "The vast majority of Americans agree that we need to do more on gun safety. That is a debate we can win if we keep at it."
Clinton also takes on those calls for her silence by simply saying she isn't going anywhere, even if she isn't running again.
"There were plenty of people hoping that I, too, would just disappear. But here I am," she writes. "As Bill likes to say, at this point in our lives, we have more yesterdays than tomorrows. There is no way I am going to waste the time I have."
Recent losing presidential candidates have found outlets after their losses -- Al Gore became a climate change activist, John Kerry and John McCain went back to the Senate and Mitt Romney has toyed with future runs.
For Clinton, though, the possibility of running again is all but ruled out in "What Happened."
"That doesn't mean I'll ever run for office again," Clinton writes. "It does mean I will speak out on the causes I care about, campaigning for other Democrats, and do whatever I can to build the infrastructure we need to succeed."
The clearest sign that Clinton isn't considering a future run is the way she handles Sanders, whom she cast as an inconsistent and hypocritical politician and accuses him of breaking a promise to not get into personal attacks. If Clinton was considering a future run, she would have to be careful with Sanders, who wields considerable power with liberal Democrats after the insurgent campaign he ran in 2016.
Clinton's memoir -- especially because of her attacks against Sanders -- has been met with derision from liberal Democrats, who view her as a divisive figure who shouldn't complicate current Democratic Party politics with a return to the public eye.
Unlike Clinton, Sanders has not distanced himself from 2016 chatter and is widely seen as someone who is likely to run for president against in 2020.
In response to the new memoir, Sanders was more careful than Clinton, telling reporters and CBS' Stephen Colbert that it is time to "move forward" and not focus on the 2016 campaign.