The point is replacing a somewhat transparent legal system with an arbitrary mess which makes everyone that isn't exactly on the politically desired line feel uneasy all the time due to uncertainty of state actions.
GOP politics and agenda are all about control. And religion historically has always been a means of control. Add a more aggressive form of indoctrination instead of education in schools so that you have young people just smart enough to profitable but brainwashed into not being free thinkers who go tribal against anyone against their tribe. Once you have people replacing morality with religion you can alter that religion to match what ever you want as a means of control.