Former senior U.S. Customs and Border Protection official, Thad Bingel says that a wall along much of the entire border may be theoretically possible but may not be desirable.
"Is it desirable? At what cost, and what do you give up to pay for that?"
"Every wall can be circumvented. People will go under it, they can go over it... no one should go into this with the idea that if you just build the right kind of wall, no one will get through"