And so what? Howard P. Kainz has a pretty fair account of how far the theology of the LDS church is from orthodox Christianity, despite its profound fascination with Jesus. But he also fascinatingly contends that "while Romney’s religion is—to say the least—heterodox, it raises fewer ethical or ideological 'red flags' than the beliefs of many preceding presidential candidates." Because Mormonism is so outside most traditional Christian denominations, and because it has an admirable history of separating church and state (most persecuted religions see Jefferson's vision more clearly than others), Romney escapes the theocratic charge that would clearly dog Santorum:

[T]he fact that Mitt Romney, the first Mormon candidate for the presidency in our nation’s history, is not only a bishop in the LDS church but a High Priest of the highest echelon (the "order of Melchizedek") within that religion, and is not being opposed because of the "separation of church and state," is an indication that Americans do not consider him a bona fide Christian. In contrast, one can imagine what would happen if a Catholic or Lutheran or Episcopalian bishop or priest sought the presidency. An impossibility! … It is becoming clear that—from the ‘ordinary’ Christian point of view—Mormon "high priesthood" is a sui generis order, possibly analogous to higher Masonic degrees, incorporated into a religion quite different from most Christian denominations.

And Romney doesn't talk about religion the way the others do. Partly because he doesn't want to highlight the Mormon issue; but partly because Mormons are less theocratic in American national politics than evangelicals or pre-Vatican II Catholics like Santorum.