Romney was not popular because he was moderate Mormon and rich. The kiss of death for successful charity giving men.
His Mormonism played little part in the election. The only ones that would be deterred because of that lie firmly with Republicans anyway.
To be fair, I usually vote Republican, but Mitt's Mormonism is what turned me off.
I really despise Mormonism, a religion built on lies (As opposed to the rest of them, built on ignorance.)
It didn't have any effect because no one talked about how batshit crazy Mormons are. The Media avoided it, Obama avoided it, Romney avoided it.