You beg the question by jumping to the assumption that the religion you cite is indeed "a force for good."
If you go to this ex-Mormon's snapshot of the fruits of Mormonism in Utah, http://www.freerepublic.com/focus/f-news/1940378/posts (post #165), you'll see it's not the "force for good" you make it out to be -- even on a social level...(an eternal spiritual level is another discussion).
I've also made the argument on several threads that a political leader who has seen his respected religious leaders shift gears on key theological tenets (polygamy; blacks as priests; Adam as God; blood atonement; exceptions granted for abortions; etc.) is more likely to feel free to swing free & loose with his own positions--especially on social positions. I mean, hey, if I think my God is at times free & loose on the number of partners, they what's the difference if I embrace gay civil unions (as Romney does) or tax-funded domestic partnership benefits (as Romney does)?
Colo, your link is no good.