John Fund of National Review Online responds to one of the most interesting revelations from a new book about retiring senator and former presidential nominee Mitt Romney.

I’ll never forget when National Review editor Rich Lowry asked me at a dinner in September 2012 if the secretly recorded video of GOP nominee Mitt Romney deriding 47 percent of Americans he called Obama voters as people who don’t “take personal responsibility and care for their lives” would cripple his campaign.

I told Rich I didn’t think so, because by November voters wouldn’t carry it into the voting booth as a top issue, and some independents would quietly agree with him. I may have been right about the voters, but I was wrong about Romney and his fortitude.

The GOP nominee apparently fell to pieces over the tape, and as late as September 30 — five weeks before the election — he was actually thinking of dropping out. Not a man of stern stuff.

We learn all this from the new book Romney: A Reckoning, which while authored by Atlantic writer McKay Coppins was done with the full cooperation of Romney.

Romney apparently went into depression after his remarks were made public, according to an excerpt of the book published Monday in Mother Jones:

“He could barely eat during the day and struggled to sleep at night, even after popping a Lunesta. He couldn’t even bring himself to listen to music in his hotel room—’just too sick at heart,’ he wrote. When he tried to concentrate on briefing materials, his mind would drift toward the self-inflicted damage he had done to his campaign, and to all the people he had failed. To take his mind off it, he rode the elliptical at a punishing pace.

“Night after night, Romney castigated himself in his private diary. ‘Stupid, stupid, stupid,’ he wrote.”