The other thing is that most of the suspected attackers weren't refugees; they were Europeans who traveled to Syria and then came back:
http://jezebel.com/most-of-the-suspe...nat-1743507304
And, of course, the majority of the 9/11 hijackers were citizens of our ally, Saudi Arabia. They weren't refugees. All but one were here on tourist or business visas (1 on a student visa).
I don't see any GOP candidates or governors suggesting we not allow people in on tourist or business visas, despite the fact that, when one uses facts and not fear-mongering, that's where the danger has historically been, not in refugees.
For that matter, since 2002, white supremacists have killed more people in terrorist attacks in the USA than Muslim radicals. But none of the candidates or governors are talking about that, either.