It is all about getting labor for cheap, illegal workers can not complain about their wages and working conditions because it is a trip to the lock-up but you say "but no one wants those jobs who are legal". Maybe so but it drives everyone's wages down because it takes the bottom out of the base wage. The wage system loses its base because the people who would normally have to do what the illegal people do, to eat, are pushed out by the folks who are not able to complain about their working conditions.It makes a false bottom to the labor market and drives down the natural wage. Policy matters. Myself, I am a free trader and that includes the free flow of labor not just goods. I would vote for a political confederation of the Americas in a heart beat. The people of Europe understand this much better at this point in time than the Americans do. The EU has drug its backward nations forward through free trade that for the most part includes the free movement of labor.