Except in a command economy, lower wages mean lower prices, so the real living wage, all other things being equal, remains the same regardless of the number of immigrants. I still say that we should simply privatize a strip of land along all of our borders and allow landowners to decide who may enter their land. Keep the government out of it.
The main argument against this is that drug dealers enter the country through immigration and they are heavily armed to avoid capture by legal authorities, thus making them a risk to the landowners. Well, legalize drugs (the war on drugs is a failure anyway). Then drug dealers would, legally, be guilty of nothing more than trespassing even if the landowners refused them permission to enter. Very few people would kill to avoid a charge of trespassing, while many would do so to avoid hard time in prison under current U.S. drug laws.

__________________
"Some people complain about the system. The system is not good, so they can't do anything. It's an excuse. Freedom is in your heart." (Jin Xing)