If Ezra Taft Benson were alive today and running for President, I would have no hesitation about supporting him even though, as a Mormon, his views on the Trinity, the nature of Jesus Christ as existing eternally and being wholly God and wholly man, the reliability of the Bible and its completeness, salvation by faith alone through grace alone, and numerous other matters differed from mine. I differ from a Roman Catholic or an Eastern Orthodox on some theological issues, and from a Protestant from the Wesleyan, Holiness, and neo-orthodox strains on some theological issues as well. Electing someone to public office is not the same as choosing an elder or a deacon for your church. Morality is important, yet one can adhere to a Biblical standard of morality even if his version of Christianity differs from yours or if he is not a Christian. Should we reject the contributions of Jefferson, Franklin, and John Adams to our nation's foundation because none were orthodox Christians? They were fundamentally moral men with respect to their public careers.
That being said, Mitt Romney is not a conservative, based on his record as governor of Massachusetts, nor are the nominally Catholic Rudolph Giuliani or the nominally Episcopalian John McCain.