Granted, Mormonism is further theologically from Protestant theology than Catholicism is. Mormons are also far more aggressive in proselytizing than are Catholics, which does not help their relations with evangelicals. However, the cultural standards promoted by the LDS Church entirely comport with those of conservative evangelicals and traditional Catholics.
There have been strong conservatives of the Mormon faith: Ezra Taft Benson, for example. My objection to Mitt Romney is not his Mormonism, but his past liberalism.
Frank Keating was Catholic. Since coming to OK in the late 90's I have not noticed a rift between Catholics and any of the Protestant groups. In fact I have been to several things where all the church's are working together.
In my State Rep race, his Mormon Church and how they interferred to get a Democrat Mormon to drop out of the race was disgusting and beyond my comprehension. I had never confronted this before.
Istook was associated with a pedofile cover-up in the 90's here in OKC for the Mormon church, sent money to Utah for their lite rail that should have come to Oklahoma, and the list goes on. The Foley former page who worked for Istook was also Mormon along with the other campaign manager. Both were put in place by the powers at be and ran the worst campaign in history.
At least where I live it was common knowledge about Istook and my State Rep being control by the Church along with votes cast by my State Rep against this district but the Church leaders wanted those bills passed so he voted with them not the district.
I wasn't a Romney supporter to begin with and then found out he was Mormon and had hired the group that ran four of our campaigns into the ground. Less than impressed and figure there must be some connection.