That is a false dichotomony. It is possible to change U.S. immigration policy to reduce the number of terrorists illegally entering the U.S. without requiring the U.S. to become a police state.Yeah. And so what? From there are terrorists, foreign and domestic ones. But that is not all government is about.
So yes, you have a point but it is a limited one, unless you want to turn the USA in to a police state in effect.