When Christian "leaders" bitterly complain about the success Trump is having among Christians, they should ask themselves what role they played in preparing for it. Admonitions that Trump's behavior is antithetical to Christian teaching comes hot on the heels of a systematic denunciation of Christian teaching and history - by Christian leaders themselves. Christian history is treated, by both Popes and protestants, as a big temporal embarrassment in dire need of apologies to anyone who will listen. Even conservative apologists deal sidestep Christian history altogether rather than defend it. Praise is reserved for people who have questioned or changed Christian teaching, the more modern, the better.
As Christian history is treated, so too is American history. Then along comes someone who decides, to hell with it - they're saying America is a fantastic place with a great history, one we have every right to be proud of and defend. Not because we can, with even more sacrifice, bleed ourselves to solve the problems of people halfway across the world (and who, incidentally, hate us.) But so we take care of ourselves and solve our own problems and even maintain our own culture. As we are justified in doing.
Why in the world would someone like that be popular? Who would ever support someone who tells them that they should be proud of the history of the institutions they identify with, rather than be perpetually and wholly ashamed of them?
It is a mystery.