That’s when Eastwood famously spoke to an empty chair, in which the actor went well over his alloted time and left most of the audience baffled. Romney’s senior strategist, Stuart Stevens, was backstage with Romney watching Eastwood, and while the Republican nominee “seemed to think it was funny — at least at first,” the authors write, Stevens was so upset by the “disaster occurring on stage” that he “excused himself, went into another room and vomited.”

In his hotel, Eastwood was listening to an oldies station and heard Neil Diamond’s “I Am…I Said,” which features a line about talking to a chair, the authors write. Just before making his entrance on stage, Eastwood asked a stage hand to put a stool on stage to the left of the podium. The result was a mixture of standup and surrealism, and while Eastwood recovered somewhat by the end of his speech, campaign aides were fuming. Eastwood later said, “If somebody’s dumb enough to ask me to say something, they’re gonna have to take what they can get.”

More from behind-the-scenes of the 2012 Republican National Convention. This time, it's a glimpse into how a senior Romney advisor felt during the now famous Clint Eastwood speech: And what prompted the chair skit?If you care to relive that surreal moment, once again, Clint Eastwood: