I've been a major supporter of building a wall with a large gate on both of our borders. One of the arguments I keep hearing against is that "they'll just go around it". I've never really had an answer for that one...until today.
It occurs to me (thanks in no part to something that Gribbit said elsewhere) the Great Wall has protected China for literally thousands of years... Hey, if it's good enough for the Israelis AND the Chinese, it ought to work for us too...