While it does appear to be legal to discriminate on the basis of religion against those that seek entry to the USA simply because they do not yet have any constitutional rights, I don't think it is right. It sends the wrong message about our nation and would only serve to placate the fears of the irrational people making arguments that don't hold any water when it comes to our safety and who we should help. As for those already here, I have seen a few comments where people are under the mistaken impression that only citizens have constitutional protection of religious choices. This is simply not true. Anybody already in the USA (excluding those in processing at entry points) has constitutional protections when it comes to matters like religion, free speech, and many other items included in the bill of rights.