What does this have to do with terrorists? It's just the same old xenophobic argument that foreigners bring strange disease's.
It was said about the Chinese, Irish, Poles, Asians, Africans etc...
We don't quarantine tourists, diplomats, laborers, immigrants or other visitors.
It's a side issue, but nonetheless important. Many immigrants, illegal and otherwise, work in fast food restaurants. If they haven't been immunized for various diseases, they often spread them. And the American public pays the price. I can remember a few years ago when my youngest son visited NY with some foreign college pals. Taiwan maybe, Asian anyway. The parents were living in NY, and had a restaurant. The mother fell ill, and my son was to visit them around Thanksgiving. He called me to ask if he should go, considering that the family would be upset. They thought she might have cancer. Happily, it wasn't. It was TB.