Non-believers have their own reasons for not wanting a religious president in the white house (look at the Bush Jr. years for an example) but it seems that other Christian groups also take a hard stance against the Mormons even to the extent of producing films which educate the public on the strange beliefs of Mormons. Of course "strange" is in the eye of the beholder as what one considers strange certainly depends on one's viewpoint.
Then again the Mormons have a lot of weird customs and beliefs - the holy underwear, the racism, the sexism, the polygamy thing, no caffeine/alcohol, the offering of the book of Mormon to ancestors, the huge hot tubs on the backs of oxen, Jesus in America, blaming wagon train massacres on the Native Americans etc. Plus the fact that the whole religion was started by a con man who was run out of town and threaten by castration. If you don't know what I'm talking about the you don't know enough about the religion. I suggest you start with "Under The Banner Of Heaven" by the always excellent Jon Krakauer and then perhaps take in the new Broadway show "The Book of Mormon".
The following cartoon, banned by Youtube after pressure from the powerful and rich Mormon church explains some of the teachings of founder Joseph Smith and his golden tablets which he claimed contain missing parts of the bible.
