What will it take to get Americans to recognize two very basic facts:

1) Travellers from the middle east (especially refugees) already go through an "extreme vetting" process.  All a ban does is remove the good (vast majority) as well as the potentially bad.

2) All a ban does is play right into ISIS propaganda: "They hate us, so we should hate them" "They won't welcome us, so we should fight them".

Simple messages, obvious and well-known, but apparently not repeated enough.