Demonizing the opposition is just wrong. It connotes a fundamental lack of empathy, which is the basis of a civil society.
Holding Romney responsible for everything that Republican candidates say is unreasonable. Excoriating him for his personal beliefs apart from his political philosophy and policy positions (whatever they are) comes dangerously close (particularly in his case) to religious intolerance.
I voted for Republicans for years even when it was not in my interest to do so, because we agreed on some basic principles. (This is no longer the case.) I never voted for Ted Kennedy--not once--because I thought he was a morally vacant spoiled rich kid.
I didn't vote for George W. Bush, because I didn't believe he had the inner strength required to lead this country; he let himself be lead instead. I voted for his father twice because I believed in his fundamental decency and integrity. I was probably wrong in that case.
Despite my scatalogical characterization of Romney on the stump or the debates, so-called, I don't doubt his ability. I think he has a fatally flawed view of how institutional relationships work, and what a President should do. He was our governor for four years, and he was not a malign force for the evil forces of darkness. Instead, he accepted working with a corrupt legislature because he had no choice, and was careful to make no decisions that might harm his chances for the Presidency. In so doing, he did basically nothing. Having taken that course in his quest for the highest office, I don't trust his judgment to do what is best for this country. I think I mistrusted Dukakis for the same reason.
Is that a double standard? Sure it is. You vote your bias, and find people who vote their own biases inconceivably stupid. That's the American way.