"I'm sure I ruffled a lot of feathers," Romney recalled in his autobiography "Turnaround." "I had been gone for a year, and they were getting along fine without me. But Bain Capital was my baby and I was back in town. I owned 100 percent of the voting stock."

With Mitt back at Bain, his parents returned to Michigan. A year later, George Romney collapsed while running on his treadmill. He died at age 88.

An unfailing optimist, George had never wallowed in his own failed campaign, and he didn't dwell on his son's either. Still, for Mitt, there was no denying that his idol's last image of him was one associated with failure.

After the loss, Mitt told his brother, "I never want to run for something again unless I can win."

Worst day

In 1997, Ann Romney felt numbness in her right leg. Then it spread to her entire right side. She had trouble getting up the stairs. Over the next year, she began having some difficulty swallowing, needing more sleep than usual, and feeling nauseated for a good part of every day.

Fit and not yet 50, Ann knew something was seriously wrong. At first, Mitt held out hope that the numbness might be from a pinched nerve. In 1998, when Ann's primary care doctor referred her to a neurologist at Massachusetts General Hospital, Mitt went along.

It was there, sitting in the neurologist's waiting room, when Mitt grasped the severity of what his wife was up against. One of the brochures he spotted was about Lou Gehrig's disease, another about multiple sclerosis. There was no brochure for pinched nerves.

Mitt turned to his wife and, seeing the worry in her eyes, said, "I can deal with anything, so long as it's not fatal."

Once in the exam room, Dr. John Stakes led Ann through a series of neurological tests — pinpricks, standing on one leg, turning around with her eyes closed. It quickly became clear she was not doing well. "When she'd stand, for instance, with her eyes closed," Mitt recalled recently, "she'd fall over."

After the doctor left the room, Mitt recalled, Ann "broke down and cried, and I shed tears with her."

The confirmation of the diagnosis as multiple sclerosis would come later, after an MRI. But it was this crushing experience of watching Ann fail test after test that Mitt would describe later as the worst day of his life.

Until this moment, his had been mostly a charmed life. He had suffered defeat as a candidate, but that could be dismissed as the folly of taking on an icon. Mitt's siblings, meanwhile, had all suffered setbacks, including painful divorces endured by his brother and older sister.