Part of me wants to write a WWZ style anthology about people telling their stories post Redcap takeover and eventually being kicked out.
So far I've got 3 world building points,
only landowning Christian men can vote, non-white Christian men are heavily discouraged by basically the Klan revived as a copy of Iran's morality police. Voting districts are exclusively alloted based on square acreage instead of population size. The legislative body is called the Holy Synod of Saint Washington.
"holy crimes" get you branded with a literal scarlet letter, one of the worst examples is that rape victims are often branded J for "Jezebel" because their attacker was able to work some connections to get out of being prosecuted, so attempting to file charges instead gets treated as admitting to sex before marriage, something that only the woman gets punished for. Rest assured there are other also terrible letters, like S for sodomite or H for heretic.
You or your family can pay an exorbitant sum of money to have you "redeemed", which instead sees you forced to wear a death mask in public as a "mortificant", yes even if you have trouble breathing in it, no this doesn't change that people will still treat you like shit, yes you'll be treated as the one at fault if someone forcibly removes the death mask while you're in public.
There is short novel called "If This Goes On..." describing a rebellion against an American theocracy and serves as a vehicle to criticise the authoritarian potential of Protestant Christian fundamentalism.
It was written by Robert Heinlein in 1940 and the theocratic takeover was written to occur in 2012.
The point is that they're doing shit that is considered heretical by most denominations and yet insisting the whole time they are true blue god fearing Christian folk.
No no, I know what you're saying. But to me your post kinda read like your story was introducing something new (maybe I didn't read it properly). I was just pointing out that the concept of "pay to sin" was literally employed by the Catholic Church before.
Don't forget the genocide against the Catholics and Mormons when the Evangelicals no longer need them.
Under prot rule atheists will be fine. We will just lie and be safe. The groups most at risk are the ones that are close to to prot but not quite there.