Well, wrong!
Since they are attracted partly because our lenient "laws" mean they don't really risk anything by trying, and the amnasty proposal gives them hope.
Meanwhile, do those Middle-Eastern Terrorists think we're stupid, or what?
I think it would be very easy for Middle Easterners to fool people by blending in as a Mexican Farm worker, his accent would give him away, but if he learned a wee bit of spanish you could take an Arab for a Mexican