Just as he began to seriously ponder a 2016 presidential campaign, Vice President Biden's 11-year-old granddaughter curled up next to him and delivered the emotional punch that framed his decision-making process.

"Pop, I see Daddy all the time. I see Daddy all the time," Natalie Biden told the vice president, according to his recounting for an interview aired Sunday night on CBS's "60 Minutes." "Pop, you smell like Daddy. You're not going to leave me, are you, Pop?"

It was late August and the swirl of speculation was mounting over whether Biden would enter the Democratic presidential contest and challenge former secretary of state Hillary Rodham Clinton, and the speculation would hang for almost two months longer. But, as Biden said in the interview, the death of his elder son, Joseph R. "Beau" Biden, hung over the family for so long that by the time they were ready to really analyze a presidential campaign, it was too late to mount a credible challenge to Clinton or Sen. Bernie Sanders (I-Vt.).

The vice president, with his wife, Jill Biden, at his side, candidly acknowledged in the interview that he no longer believed he could win the race because he had waited so long.

"It just takes time," he told Norah O'Donnell of CBS, explaining the emotional tug of war. Some mornings he woke up and just wanted to cut off the process, but Jill Biden — who had decided that her husband would make a better general-election candidate than Clinton, Sanders and other contenders for the Democratic nomination — pushed him to continue thinking about the race.

By Tuesday night — after a day filled with events that seemed to jab at Clinton — Biden told his wife and younger son, Hunter, that he didn't think he could mount a third campaign for president. His wife hugged him, and less than 24 hours later, after 43 years in elective politics, Biden, 72, announced in a Rose Garden ceremony that his political career was over.

The vice president did not endorse Clinton's candidacy for president and said good things about Sanders, but he used the interview to focus on his shifting role into Democratic elder statesman without a specific portfolio.

"No. No," Biden said when O'Donnell asked whether he would run for office again or whether he was leaving the door open to taking up the campaign if Clinton politically collapses. "I can do so much more, I believe. I hope I leave office in — as a respected figure who can — convene people and bring people together."

Ultimately, Biden said, his decision came down to emotional suffering: the inability to overcome the loss of his 46-year-old son in a time frame that allowed for the vice president to assemble a legitimate campaign with the Iowa caucuses now less than 100 days away.

"I've said from the beginning that I don't know whether our ability to deal with the loss of Beau would reach a point where we could do that before time ran out. And — and there was nothing we could control," Biden said.

The family is beginning to recover, he said, pointing to time they spent in Delaware over the weekend, when Joe and Jill Biden got to watch their granddaughter finish a cross-country meet.

The vice president gave her a big hug. "Daddy would be happy," Natalie Biden told her grandfather. "Wouldn't he? Wouldn't he?"