Actually, I have very good LDS sources, and they tell me that your take on their church's position is wrong. They teach "Thou shalt not kill, nor do anything like unto it."
But, Orrin Hatch said he "got a revelation" and a couple of his fellow LDS members in the Senate have followed along.
A horrible way to make public policy, or decide matters of life and death.
I suspect your sources are wrong, and to suggest that Hatch is free lancing, via a personal "revelation," that is not LDS theology, seems quite incredible to me. I don't believe a word of it.