Beau Biden

"Joe is 81... but he's 81 doing more in an hour than most people do in a day. Joe has wisdom, empathy, and vision," Jill Biden wrote in an email to donors. "His age... is an incredible asset."

The former vice president is out with a book that recounts in heart-wrenching detail his son Beau's diagnosis and death from brain cancer — and his deliberations about running for president.

The death of the vice president's eldest son derailed his own hopes for the White House. But he once had better approval ratings than Hillary Clinton and may have been a more competitive nominee.

The life of the Iraq War veteran and former attorney general was honored at a Catholic ceremony in Wilmington.

"It's not all that difficult, folks, to be compassionate when you've been the beneficiary of compassion in your lowest moments," the vice president told Yale graduates in May.

The former Delaware attorney general is being treated at the Walter Reed Medical Center in Bethesda, Md. In 2013, he underwent surgery after being diagnosed with a brain lesion.