(Reuters) - Texas Governor Rick Perry's embarrassing inability to remember a government department he would eliminate if he became president, perhaps the biggest gaffe of the 2012 election campaign, was due to chronic lack of sleep, a new book says.
"Oops," a diary of covering the Perry campaign by Texas Tribune correspondent Jay Root, says Perry suffered from insomnia for weeks before the gaffe.
The blunder occurred during a Republican presidential debate in Rochester, Michigan on November 9, 2011.
Trying to recall the three government departments he would eliminate if he became president, Perry said: "I would do away with the Education, the, uh, Commerce, and, let's see. I can't. The third one I can't. Sorry. Oops."
He paused for an agonizing 53 seconds before conceding that he could not remember the Energy department, the third agency he would close.
Book author Root, who covered the Perry presidential campaign from the summer of 2011 to its end in early 2012, said Perry had battled insomnia most of the campaign.
Perry stumbled in several debates and at one debate in Orlando, Florida, one of his answers was almost incoherent.
"Perry had kept in touch with his medical team, and by early October, days after the Florida fiasco, the campaign had urgently consulted sleep specialists, bringing them in to investigate.
"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," Root says.
Perry's unraveling began in earnest after back surgery in mid-June, 2011. The Texas governor took pain killers for a few weeks after the surgery but refused to continue them because he said he wanted to be mentally sharp for the campaign.
By October, Perry was diagnosed with sleep apnea, a chronic condition in which a patient sleeps so lightly that he is constantly waking and breathing can stop for a moment. Perry was given a machine that helps breathing become more regular during sleep.
But at the same time he complained of pain in his leg and foot that might have been a result of the surgery. This kept him from sleeping, Root says.
A request for comment from the governor's office on Saturday did not receive an immediate response.
(Reporting by Corrie MacLaggan; Writing by Greg McCune; Editing by Todd Eastham)