Well, there is one YUGE problem with your logic.
The wall isn't to keep out illegals. We need them to pick our crops. The bused and flown in. (as you have said) Further, talk to anyone in mexico, and they say that many people are returning.
No, the wall is to keep americans in.
To keep americans from escaping when the police state is ratcheted up even more. And the economic system is collapsed.
RE: Why the "Border Wall" won't be built for decades!!!