Let me second her "water is wet" statement of plain truth: Mormonism is not Christianity. If you want Scriptural reasons, just do a quick Google search.
Do Christians support Mormon candidate Romney? Indeed. I do.
Do Evangelical Christians agree with Mormons when they say, "I'm a Christian!" as they segway into prosthelytizing their real beliefs rooted in the Book of Mormon? Nope.
So why all the hub bub? Because Mormons sell themselves as Christians while Bible-based--and Bible-based only--Christians strongly disagree.
This is great fodder for the MSM.
UPDATE: If you don't want to Google, Derek writes: "The Book of Mormon, although about Jesus Christ, contains a different Jesus than traditional Bibles who is not the only begotten Son of God, the second person of the Trinity, or the one through whose death on the cross we can be saved from our sins. Hence, Mormons are not Christian according to God's very word, not my or anyone else's determination."
UPDATE: Albert Mohler, President of the Southern Baptist Theological Seminary sums it up like this: "Mormonism holds that God is an exalted man, with a physical body. Christianity teaches that God is Spirit. Mormonism denies the historic Christian understandings of the Trinity, the person and work of Christ, and the doctrine of salvation. Christianity promises salvation through Christ's atonement and the sinner's justification by faith. Mormonism promises deification. Christianity calls for personal faith in Jesus Christ. Mormonism calls for obedience to its own teachings as the path to exaltation. Mormonism replaces belief in the sole authority of the Bible with other writings, including the Book of Mormon. This list is only a brief summary of the vast chasm that separates Christianity from Mormonism. Put simply, Mormonism is not just another form of Christianity. It is a rejection of historic Christianity."
But even if we or an angel from heaven should preach to you a gospel contrary to the one we preached to you, let him be accursed. As we have said before, so now I say again: If anyone is preaching to you a gospel contrary to the one you received, let him be accursed. (Galatians 1:8-9)