A Mormon as President? Why not?

I decided not to make this have a clever title, nor to drone on about my own opinion here for overly long because I wanted to mainly drop a simple question out for consideration.

I know Mitt Romney in particular has a few personal quirks that someone might not like to see in their presidential candidates, like the fact he's waffled on a few issues, but set those aside and ask the generic question. What's wrong with having a Mormon in the White House?

We're looking at an election year where we're likely to see a demographic breakthrough for our leader. The next President is likely to be either Black, female, Hispanic, Mormon, or Italian. While I think we probably have come to the point in this country where race matters very little, we do still care about gender to some degree, and we certainly care about a person's beliefs, as they should say something about that person. While I tend to mostly disagree with the reasons people feel a woman does not belong in the Oval Office (yes, women are different, and they lead differently; is that necessarily so bad, though?) I seriously don't get the Mormon thing.

Sure, I don't think that Mormon theology is correct. In fact, I think it's rather strange. But what issue is that insofar as being President? The President isn't going to be teaching the country about God. They're not going to be explaining scripture to us. We're voting for a political leader, not a high priest. Mormon moral values are pretty darned American, as far as I can tell. There is a very short list of religious affiliations that I would hate to see our President have, and Mormonism is not on it.

What is it that people realistically fear a Mormon President would or could do to this country? I'd like to know, because I frankly don't see it.