Jesus said to...
This is a Christian country, if one is to believe what the right has been trying to sell.
So why would we, or how could we, not do what He said?
Logically, sure, the US gets along just as well without them. Yeah, some of them become a burden, or welfare queens, or whatever. We might even admit an actual terrorist.
We grow all of those things right here all on our own.
The downside of a blanket refusal to accept any?
Recruiting tool for IS, plays right into their "narrative". The US is seen as a hypocritical bully state in huge parts of the world. Lots more fighters sign up to fight the evil US.
Stuff like that.
Ironically, and sadly, 22 governors and FOX etal have already given them the TV footage to,support that claim regardles of what we eventually do.
Brilliance... Not!
Better to say we will take them, and then vet them soooo carefully that none ever get in, if one is somafraid one is willing to disobey Jesus. We get the good headlines, no one has to be afraid of "those people"