Well, I wouldn't go quite that far. I reject Mormonism as a false religion, but not every false religion is a "cult." The term "cult" implies a certain set of characteristics: a powerful, charismatic leader; sleep deprivation and cutting off new recruits from their families; etc.
Now while I reject the LDS religion theologically--it is not a Christian church body, since it does not hold to the historic, biblical, creedal, Trinitarian, Christological faith--that in itself would not be enough for me to disqualify Mitt Romney from being President. I am voting for President, not Pastor. And Mormons can make for good citizens; often they are fine, upstanding citizens.
If Romney ends up being the Republican nominee, and I think he would govern in a conservative, constitutional way, I would not hesitate to pull the lever for him.
Right now, though, I am supporting Fred Thompson, since I like his stand on the political issues best of all. And Thompson isn't much of a church-goer, by his own admission. Again, I'm voting for President, not Pastor.
I would never vote for Giuliani, the nominal Roman Catholic, not because of his Catholicism (which he doesn't even practice), but because he is a liberal. I would vote third party or write-in before voting for Rudy the RINO.
I'm not crazy about Huckabee, who apparently is an ordained Baptist minister, again because of his political views--the Bush Lite variety of "compassionate" conservatism.
While I agree that Mormonism isn’t a cult, it’s virtually impossible to leave. Our church in Salt Lake (ELCA) was about 25% former Mormon, almost all of whom were still carried on the LDS rolls. Keep that in mind when you hear/see figures on the growth of that particular faith.
Oh, and the Salt Lake valley (as is much of Utah) is a closed community religion-wise. By that I mean it’s very unlikely a ‘Gentile’ (non-Mormon) will be accepted. Business interests are the exception, but once business is concluded forget the relationship.
I could go on and on, but suffice it to say, My wife will never cast a vote for Romney because of his religion. I would, but would do so with much concern. Like you, I’m for Fred. But, time will tell.