This goes both ways: (1) a ban on a country is usually there for a temporary reason of leverage on leaders/system of government on which the citizens may have

This goes both ways: (1) a ban on a country is usually there for a temporary reason of leverage on leaders/system of government on which the citizens may have a varying degree of control through different means. (2) However, a ban on a religion which has many movements (some of them infighting), and radically opposed views and some crazies, on which the majority have no control or relationship with whatsoever could seem more wrong. (1) is trading on an existing system of unethical attributes (2) is creating an additional one. Let's not forget that the USA was founded by people who were looking for religious freedom and peace from prosecution. A test on specific beliefs is much more appropriate and actually already implemented on immigration forms (e.g. questions on polygamy).