Even if a person starts with the premise that all politicians lie to one degree or another, the shear number of 180 degree shifts of Romney's so-called sincerely held philosophical beliefs and his policy support flip flops is mind-numbing in their scope.
When you add to that the fact that even conservatives don't really trust his pronouncement that he's an "severe conservative," Romney simply can't afford a contradiction to his claim that he left Bain in 1999 if it's later shown that he was actually still in charge and that report is all but etched in stone with a paper trail that contradicts what he's on record as saying.
Hey, it's one thing to flip flop on the issues. It's quite another think entirely to make claims that are later shown to be patently untrue. After all, would could Romney's argument be at this point? Is he going to argue that he was somehow still legally responsible for Bain, but he didn't know it? Does he actually expect people to believe that he was a GREAT businessman if that's the case? And why should anyone respect or trust him when it comes to negotiating with America's adversaries if he's so foolish in his own business dealings?
But, of course, conservatives will defend him...while holding their noses and cursing him under their breath.