"Their dedication is to the church. You leave the church and see what happens. A true Christian is simply a Christian. His denomination is irrelevant. A Baptist can worship in a Presbyterian church and a Presbyterian can worship in a Baptist church. I can go to a Catholic church and worship there even though I am Protestant."
You cannot take Catholic communion unless you are baptized in the church. You cannot participate in all sacraments if you are a protestant. There are theological differences that in the past were viewed as important, but in our secularized world seem quaint and obscure.
Highlighting the differences with Mormonism is a theological matter, but I dont see it as a politically viable one.
The question a Christian voter needs to ask is:
Is the values he espouses and lives by my values?
For Romney, he can make the case that his faith, his belief in family, etc. are aligned with Christian voters.
In 2000, almost half of America voted for a Jewish Vice President. It wasn't an issue. I don't see how this will be an issue either.
Protestants don't believe in transubstantiation which is why we don't take Communion in Catholic churches.
Politically, I don't care if someone is Mormon.
Note: Someone mentioned "sheep stealing" earlier regarding the Mormons. I find this interesting because my neighbor is Mormon and he's been very good to invite me to his church. The elders even came by one day. In the non-Mormon church, this is considered rude and is referred to as "sheep stealing". If your neighbor is a good Baptist, you don't invite him to the Methodist church in order to get him to join your church.
Well, except for the Episcopals. Everyone is trying to steal them these days.