This is not intended as a defense of mormonism, but don't all religions demand the ultimate loyalty? I don't know of a single religion that says it's okay to put loyalty to a human government ahead of its understanding of A-mighty G-d.
G-d comes first. Not family, not country, not civilization, not self, not anything else. Only G-d. Anything other than this is idolatry.
But in the case of Romney, his loyalty is first to Mormon Church ORGANIZATION over Country...not to God.