“The most relevant fact is whether my family and I have the emotional energy to run,” Biden said, adding that he has no set timeline for himself to make a decision.

Biden’s eldest son, Beau Biden, died of cancer in May.  His first wife and young daughter were killed in a car accident in 1972.

Biden said that the much-discussed mechanics of a potential presidential campaign, including fundraising, timing and logistics, are playing no role in his decision-making process.  “The factor is, ‘Can I do it?  Can my family?’  The honest-to-God answer is, I just don’t know.”

After a pause, he turned to his friend and host, former ambassador Stuart Eizenstat, and said, “But I have to be honest with you and everyone who’s come to me. I can’t look you straight in the eye and say now I know I can do it.”