Just my .02 :
There are plenty of mormons who will, given the choice between a mormon candidate and a non-mormon candidate, vote for the mormon candidate, regardless of platform. Perhaps they feel like they can "trust" that person to legislate without having to do their own research. This has backfired a lot, IMO, but so it goes.
There are also plenty of mormons, myself included, who do not care about a candidate's religious leanings.
As a regular participant in the voting process, I don't recall many (any) candidates that actually used their religion as part of their platform, unless you count their campaign mailer with a picture of them and their huge family.