Thank you for blocking the Syrian refugees. Those of us who are older remember that WW II had its Nazi sympathizers. Also we had to put Japanese in camps because we could not be sure of their loyalties. During the Cold War, the Communists had their "fellow travelers" and we were not always sure who they were.
Now in this war with ISIS, again we don’t know who is who. We do know that after 9/11 there were celebrations by Muslims. Who are they? We also know that many Muslim countries were slow to repudiate the attacks. Even in the US the responses came very slow. Why?
So how do we separate the radicals and the fellow travelers from the rest. We really don’t even know that if push came to shove there are any "rest." We have no way of knowing. And we have historical reasons to know "things are not always as they seem; the first appearance deceives many." Phaedrus