We covered this on the first page. JD said it better than I did:
Your semantics matter at least in part from a policy perspective on how you fight the threat and what the most effective refugee policy might be.
An English native home grown non-refugee inspired by ISIS on-line activity/popoganda poses a very different challenge than a refugee and/or former ISIS fighter. An immigration ban isn't gonna address the former in any meaningful way and could even exacerbate the issue.
ISIS needs to be stopped. The discussion, for me, really centers around both how you do that and how you make your citizens as safe as possible while doing so.
That being said, I am all for greater border security and vetting. Not convinced a complete or even temporary ban being pursued is the best policy decision or even really feasible.