What punishment do you suggest is put on the businessman for the illegal comming into the country, because that is in effect what your suggesting. Illegals are breaking the law weather they are working or not, and punishing an employer because he has an employee thats breaking the law makes no sense.
How do you punish the employer that has recieved proper paper work from an illegal, I guess the employer will now be responsible for policing all documents... That should be a gas especially when an employer starts digging into your background. How much power do you give the employer relative to looking into somebodys background.
If you allow them to look into your illegal residence status then is the employer going to be allowed to look into other areas of your life in which you may be conducting illegal activitys, and why not.