"I'm sure most would say crime, but that's just not a compelling argument. We will never have a bulletproof immigration system, people will find ways to sneak through went we don't want to let them in. More importantly, crime isn't a foreign problem - we have domestic crime that has nothing to do with immigrants."
So let me rephrase: "we have already some internal crime so there's no point trying to limit another source of crime" ?
As far as I'm concerned, it isn't my right to tell someone else that they can't live here. If someone wants to come to the US to try to make a better life for themselves, I wish them the best of luck and hope they succeed. I don't think its anyone's right to claim the right to decide who is worthy of getting a chance here.
When it comes to crime, its not that we already have crime so don't bother. We have to deal with crime either way, and the potential benefit of closing borders isn't worth stepping on what I consider a fundamental right. We also haven't answered how to know who will commit a crime if they come here, unless we have precogs hidden away in a pool somewhere.
So let me rephrase: "we have already some internal crime so there's no point trying to limit another source of crime" ?