"I'm with her", was a campaign slogan of Hillary Clinton, whom the Vermont senator fought against ahead of her nomination last July.
Journalists Jonathan Allen and Amie Parnes have been attracting major media attention recently due to the release of their new book, Shattered: Inside Hillary Clinton's Doomed Campaign. The president, who had hit the campaign trail hard for Clinton, now believed the race was over and was determined that she accept her defeat with "dignity".
With results coming in for key swing states pointing to a Trump win, Mr Obama called Mrs Clinton and told her: 'You need to concede'. It wasn't until he repeated his demand to Clinton campaign chairman John Podesta that she finally conceded and gave Trump a congratulatory phone call.
Kaine received a congratulatory call from then-President Obama shortly after Clinton formally asked him to fill the role and Kaine agreed. At last, Clinton said, "Give me the phone".
The book sheds particular light on the painstaking turn of events on election night, as Clinton watched the returns deviate dramatically from the path her campaign had so confidently predicted.
The book's apparent consensus is that Clinton "bears the blame for her defeat", due to self-inflicted wounds and running a campaign of constant infighting and disarray.
On Election Night, Allen and Parnes write, Clinton and her top aides were holed up at the Peninsula Hotel, just a block from Trump Tower in NY.
In retrospect, maybe the whole "I'm with Her" thing was a mistake.
"It wasn't just Sullivan in her crosshairs", Allen and Parnes wrote.More news: FDA further restricts pain medication use in kids
Clinton conceded the loss publicly the next morning.
In terms of numbers, the adviser suggested that the Clinton team account for that unknown factor by adding "three or four points to whatever they say about his support" in polls.
She admitted that she had let herself, Obama, her party and her supporters down.
A rep for Clinton said, "It was our campaign".
Much of the post-election analysis has criticized Clinton and her campaign for focusing on "reach" states such as North Carolina instead of putting more resources in the upper Midwest.
That's what Obama told Clinton by phone in the wee hours of the morning on November 9, around the time her campaign chairman, John Podesta was telling supporters they wouldn't hear from Clinton just yet, around 2 a.m.
"Shattered" underscores Clinton's difficulty in articulating a rationale for her campaign (other than that she was not Donald Trump). Barack Obama's primary victory in the state to that of Rev. Jesse Jackson.
She said: "Congratulations, Donald".
Clinton must have winced again when, later, her husband, Bill Clinton, tried to console her by comparing her loss with "Brexit". "If this had been the biggest issue her campaign had, they wouldn't be sweating it today.in a normal campaign, especially of this size and magnitude, I don't think something like this would have happened".