Illegal immigrants may be devestating for taxpayers and for American workers, but by serving to depress wages, they are great for American employers. And that's the real reason that the government is encouraging illegal immigration. ;-)
They are essential for a growing economy. Without immigrant labor (Irish, Jewish, Chinese, Polish, Indian, Mexican, German, Italian, etc...) our economy would have stagnated long ago. Legal or illegal, there's no difference. They come because we need them.
Don't be an economic girlie man.