"Keep the Muslims out, or we're in big trouble."
You would think so, except for the fact that we've had them for a bunch of years- especially around Dearborn, Michigan and Patterson, NJ - yet you don't hear about situations like they have in Europe. You don't hear any negative stories actually- I just see them running convenience stores where I live.
Why this is I'm not at all certain, but it is the case. The 9-11 murderers were not American green card holders or citizens.
The 9/11 terrorists were all (or almost all) legal immigrants. I think some had overstayed their visas, but otherwise, they got here legally.
As for your convenience store owners, a few days ago, I attended a trial of a Pakistani convenience store owner who had worked out (or probably been told by his handlers to work out) an elaborate bank fraud-money laundering scheme to buy and sell convenience stores and send the proceeds of the fraudulent transactions to terrorist groups in the ME. He had one of the most expensive criminal attorneys in the state, btw, and pleaded guilty, thereby indicating that there was a lot going on that his handlers did not want him to reveal in a trial.
Your local Pakistani convenience store owner may be a very nice guy, but he is totally controlled by people who are not very nice, and they have a gun to his head.