Come on Brandon! Get off that high horse. It is a reasonable question. Would he defy a Mormon leader who he believes is relaying the word of God?

I know that it sounds far fetched now, but if, say, the confrontation with Islam became much worse, then the religion dimension could become huge. I think a Catholic President would defy the Pope if he believed it necessary for the security of the USA. Could Mitt? Would Mitt?

The Catholic President would not fear excommunication, shaming, and being cut off from his family. That really does happen to Mormons who are deemed to be apostate. I am sure Mit has done it to others.

This could work the other way too. Suppose he is a very good president who achieves liberal reforms that his church does not like. The discipline of LDS is such that the Church could campaign against him having a second term. That would just be be democracy, but you have to factor in the discipline of LDS overcoming free will.
It is a vulnerability for the Chief.