I don't have time to compile links and quotes, but it seems that an awful lot of Republican candidates and pundits doth protest too much over the whole "Mormonism is a cult" thing.
Seriously? Where has everyone been? I was taught precisely that from the earliest time I can remember, even in my relatively sane, more or less moderate evangelical church growing up. And I know I am not alone in this.
To have strong religious convictions is to believe them at the expense of all other possibilities, by definition. It is to believe that you are right, and everyone else is wrong. If you think someone else's vastly different spiritual path is just as valid as your own: you may be spiritual, you may be open-minded, and you may be very observant of the cultural rituals of your professed faith...but you aren't particularly religious.
This is one reason why religion is not a very good rallying point for politics in a pluralistic society. Once upon a time our politicians recognized this, and tended to keep that shit to themselves.