The point of analysis and review for admissibility has to be upon application to enter the country.  Not at the point of birth.  Not at the point when a person or the person's family chooses a religion.    We are a country that is led by individuals very susceptible to political (as opposed to legal)  forces.  The legal forces, the force of law and constitutional authority, act as a balance to political force run amok.  Today, people don't like Muslims and Middle Easterners (whether or not they have a proclivity toward radical religion based terrorism.  They are suspicious and therefore hated because of their nationalities, culture, religion and color of their skin.  In yesteryears, it was the Irish, and the Jews, and the Japanese, and the Chinese.  In any given community, there are majority political forces that would openly discriminate based on national origin, religion or color.   That sort of behavior, or anything approaching or close, cannot be allowed to foment.