A Republican Florida state committeewoman, Liliana Ros, was shocked by Perry’s apparent physical distress when she greeted him during a commercial break at the debate. “He grabbed my hand and held on to it,” Ros told reporters. “His hand was so cold, like ice. And he was sweating. I don’t know what it was, but something was definitely wrong.”

It showed onstage. Toward the end of the debate, Perry had scrawled down on a sheet of paper an attack line he wanted to use against the ever-waffling Mitt Romney. But then he proceeded to botch it, turning his rambling answer into a late-night comedian’s dream.

Back at headquarters in Austin, Perry’s health — his severe lack of sleep, mainly — became a central focus. “Our guy’s not sleeping,” Dave Carney said in the office in a brainstorming session about the governor’s condition.

Perry had kept in touch with his medical team, and by early October, days after the Florida fiasco, he had urgently consulted sleep specialists. After conducting overnight tests on Perry, they produced a rather startling diagnosis: He had sleep apnea, and it had gone undetected for years, probably decades.