[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2010/images/01/08/art.palinbiden.gi.jpg caption="McCain aides feared Palin's debate performance could prove disastrous."](CNN) - Former McCain campaign manager Steve Schmidt is revealing new details on just how uneasy campaign aides felt about then-vice presidential candidate Sarah Palin's prospects heading into her debate with rival Joe Biden.
In an interview with CNN's Anderson Cooper set to air on 60 Minutes Sunday on CBS, Schmidt said Palin's debate preparations were going so poorly that campaign aides feared the closely-watched debate could prove to be a "debacle of historic and epic proportions."
The interview is part of a preview of the upcoming book "Game Change: Obama and the Clintons, McCain and Palin, and the Race of a Lifetime," by political reporters Mark Halperin and John Heilemann.
What was most troubling, according to Schmidt, was the fact Palin repeatedly confounded Biden's name during the preparation process, referring to the then-Delaware senator as Sen. O'Biden. Aides were so worried that such a mishap in the actual debate would prove catastrophic that they advised her to simply refer to her opponent as "Joe."
"It was multiple people – and I wasn't one of them – who all said at the same time, 'Just say, Can I call you Joe,' which she did," Schmidt tells Cooper.
Palin herself addresses that moment in her memoir released late last year, "Going Rogue."
"We had no idea my mic would already be hot when I walked onstage, crossed over to his turf, and said, 'Can I call you Joe?' The 'expert' post-debate analysis was that my question was a cleverly devised strategy to disarm my opponent. Yeah, right."
Schmidt and Palin have been engaged in a war of words for months, during which Schmidt has openly questioned Palin's viability to be president and Palin has accused Schmidt of mishandling her during the course of the campaign.