[Post-debate Footage] The McCain non-handshake:
In high school, we called this "the psych." Now, if McCain were to execute "the ultimate psych," he'd have followed up this maneuver by looking away, lifting his hand to his head and smoothing back his hairplugs. But, of course, he can't--y'know, hero injuries.
The fact that McCain is physically incapable of the ultimate psych may be why he, oddly, seemed to offer his left hand after it was too late.