which would have been early 70s and coincident with the Southern Strategy kicking off (as a backlash to the Civil Rights Act, Voting Rights Act, and desegregation)?

Scare the heck out of people relentlessly and you win them over.

It is critical to understand that a certain segment of right wingers has hijacked the name "Christian", and that our reaction to this fascist cult is not aimed at all who call themselves Christian.

Much of American Christianity is being subverted...

Political Christians rather than Christians of faith.

Trump's followers are the public face of Christianity in America today.

‘Real’ Christianity advances the belief that mankind at its very core is rotten, sinful by nature and in need of redemption by one specific imaginary godman, and that any and all who reject said redemption by said godman are destined to spend eternity after death burning in hell. That includes ones children, neighbors and Uncle Ned.

One need not be a Christian nationalist to hold such beliefs. Indeed, all Christians hold such beliefs. They just don’t talk about them in polite society, or they cherry pick verses and beliefs to ignore, or they mix in a dollop of enlightenment thinking to temper the inhuman horrors so clearly limned in their holy book. But limned such beliefs are. There’s no getting around it.

Much of what's in the Bible is illogical, demonstrably false, based on cult thinking, rationalization for cruelty, or all of the above.

Another category would be the irrelevant stuff, like the "begats", historical claims and anything remotely scientific sounding.

It seems that the 1st amendment allows for belief in this stuff or any other religion, but ONLY the beliefs, not necessarily the actions.

The cult has taken the first amendment as permission for anything they claim is freedom of religion; it would take days just to describe all of the evil that has been perpetrated under this claim.

I think that there are many people who want to practice "good business" -- driving hard bargains, paying under the table, evading taxes, rent seeking, shortchanging, union busting, etc. (not that I view these practices as good in any way) -- but also want to participate in "Christianity" for the group inclusion.

Republicans eventually showed up with "good business" and "Christianity" mashed together as a fait accompli, and some people chose to eat it up. But when the combination they offer is examined closely, it doesn't bear a lot of resemblance to what that Nazarene reportedly taught.

Big names like Jerry Falwell and Bob Jones started coming together to fight desegregation in the late 60s as Nixon, of all people, was directing his administration to not give grants, etc. to institutions that discriminated racially. Both of them plus others had private schools that were eligible if they allowed nonwhites in. Even though Nixon started it, they tried to blame it on Carter and toward the end of the 70s they realized it was a nonstarter. But they liked the access to power they got when they banded together and decided to pick a new issue, and even though they hadn't cared about it before, they chose abortion.