Joe Biden knew he was capable of beating Hillary Clinton in the presidential race - but decided not to run fearing a 'stop at nothing' campaign by her backers, the former vice president has revealed in his new memoir.
In Promise Me, Dad: A Year of Hope, Hardship, and Purpose, set to be released November 14, Biden reveals how he wrestled with the idea of running for office before and after his son Beau's death, and even admits he did not want to be Obama's vice president in 2008.
The book documents Biden's life as President Obama's tenure drew to a close and the media's focus had shifted to the prospects of the presidency.
It is certain to fuel the bitter infighting in the Democrats which has lasted since they were shocked by Clinton's defeat a year ago Wednesday.
Biden offers little direct personal criticism of Clinton but his message is unmistakable.
'My numbers on trustworthiness, honesty, and empathy were as high as they had ever been. And I was strongest where the most formidable candidate, Hillary Clinton, was weakest: the key swing states like Pennsylvania, Ohio, and Florida,' he writes.