He didn’t “defy his church.” There is no evidence that he ever had anything to do with abortion in his personal life, and there is evidence that he counseled against it in his ecclesiastical life.
Some Mormons have the libertarian view about abortion — kind of like the Mormon view of smoking. While we do not smoke, we generally do not favor laws prohibiting smoking because we favor freedom. Some take the same position with respect to abortion, and the church has never said they could not. That’s the position Romney took in his Mass. political races.
He defied his own church's teachings. You can spin it all you want, but it's pretty pathetic that Mitt didn't adhere to his church's pro-life dogma in making his political calculations. I guess power trumps principles, eh?
Well, that makes sense after all abortion and smoking are so similar.