Religious leaders claim to be pure in thought and word, but time and again it is proven that in private, or at least away from the cameras they can swear with the best of them.
The former Mormon Prophets Thomas S. Monson, Gordon B. Hinkley and Ezra Taft Benson were all notorious for bringing their staff and family to tears with foul mouthed and vicious tirades of brutal language, Benson's own grandson (now a political satirist and cartoonist, and outspoken critic of the LDS) recalls "Grandpa" calling him goddamned little shit as an infant.
Trumps rough tongue won't alienate him from the evangelicals they will see it as a sign of strength.

Idiots

These people are stupid, remember?

All he'd have to do is show up at a rally, holding a rifle and an anti abortion sign, and his previously angry devotees would be throwing their panties on stage.

They'll forgive him and his support will hold

Actually I have two acquaintances in this camp. As long as he was anti-abortion he could rip kids from their mother's arms, destroy the environment, you name it but say goddammit or fuck and that's a bridge too far.

If that's what it takes to get fools to turn their backs on the "anti christ"/dumb ass.

I wish there was something he could do to loose his base, I am sure he would do it.

Evangelicals don't tend to think rationally, as long as he's draped himself in the flag and it's not too obvious that he's shooting jizz into the bible they'll stay with him.

Nah, he could shoot someone on the corner of fifth avenue and they'd still be with him.