Agreeded, yet the truth hurts ambitions
I think that the statement "Miami is a third world country" is innaccurate, but the point is reasonably close.
He would be better talking about how to fix the problem, and not just fences, but a whole range of solutions from a web verification of citizenship, to punishing companies that hire illegals, to punishing states that cater to illegals, to punishing illegals, to punishing Mexico for sending them here and not providing a free democracy.
There are plenty of solutions that can be discussed.
Attacking a huge city in a key state is not how to do it.