For those who are angry at Donald Trump for suggesting that he will build a wall to separate the United States and Mexico, have no reason to actually be angry at Donald J. Trump. It will be rather difficult for him to build a wall where there is already a wall that separates the United States and Mexico. These photos were taken in California separating San Diego and Tijuana. As you can see Mexico has a lot of houses and businesses near the border, but there was not very much on the United States side.
It is the same thing as if you want to keep trespassers off your land. You put up a fence. Does it completely stop them? No. Does it deter most? Yes. If you don’t think a wall or fence work, try asking Mongolia how well a wall works. Fencing companies aren’t going out of business anytime too soon. Why do you think that is? Because they do work.