That's a wild oversimplification. Illegal aliens work for less than citizens and legal residents because their labor is illicit. Also, the true cost of their labor is hidden by taxpayer goodies for illegals like emergency room care, declines in property values in neighborhoods taken over by illegals, etc.
In addition, there are now cultural barriers to legal workers in industries that are taken over by illegals. It's not just that Joe 6 pack won't work.
"the true cost of their labor is hidden by taxpayer goodies for illegals like emergency room care, declines in property values in neighborhoods taken over by illegals, "
Aren't those costs incured by having that American who won't take that job being unemployed anyway ?
If the American took the job, we would save half of it... the unemployed Mexican would go home...