Romney's biggest problem is that if he were to be elected, 300 million Americans would have to come to terms with having a president named after a baseball glove.
Personally, a candidate's Vietnam era history means absolutely nothing to me. Whether someone enlisted, got drafted, joined the National Guard, got a deferment, went to Canada, or went to jail makes no difference. There's nothing dishonorable about any of those choices. What was dishonorable was a senseless war that made the choices necessary in the first place.