The one thing that will absolutely turn conservatives off completely is really understanding Mitt's religious beliefs. Sad but true. It should be his lies, greed and lack of character... but if they knew that Mormons believe that all other religions are "corrupt" and "abominations" the desertions would begin.
Then if you throw in that they believe in multiple gods in multiple worlds like the imaginary planet "Kolob" and women can only get to heaven with a mans help or that blacks and women are not fit for priesthood or that the virgin Mary wasn't virgin? Trouble in Romneyville!
Of course you would have to keep the message short and simple, conservatives have short attention spans. However if they were to keep researching and find that a 12 year old boy suffering from guilt over his sins for two years, suddenly claimed he had had a visit from god and Jesus who incredibly forgave all his sins and said all existing churches preached false doctrines. Oh and the spirits said it was way cool to have lots of wives! Of course much like when some wackadoo sees Jesus or the virgin in a pancake or a tree stump, the weak minded sheep began to follow and a new "religion" was born.
Seems right that when ole Joseph Smith was in charge he was also perfect for the job! He and his family believed in "folk magic" which they used (unsuccessfully) to search for buried treasure. Oh and these guy's believe that a good Mormon 'man' can become a god himself. Maybe even of the planet Kolob.
In terms of Sin, the Mormons believe that all mankind will be resurrected and saved at the last day. The slate wiped clean. No wonder Mitt feels safe telling so may lies. Can we really be surprised by all the fiction and made up facts coming from Romney? Or that a religion that does not believe in charity has produced such a greedy vulture capitalist?