In order to immigrate legally, there are rules. One of the rules is that for certain types of immigration and/or green cards the immigrant has to be sponsored by an employer.
The way to disallow it is to have a rule that says that the immigrant cannot replace an American worker. And that the employer has to prove that there are no American citizens to take the job. Most countries have rules like this.
That makes sense. But I think there are already some rules like that and companies get around them. Like making up different job titles, or replacing employees with consultants. It seems I read something about companies having to "prove" there were no Americans for the HB1 Visas.
Human nature being what it is, every time the govt. tries to control people, people tend to find a work around, often making the situation worse. The scammers end up profiting and the honest people miss out.
A couple examples:
In Santa Barbara, years ago they had a law that new housing realestate could only get X amount of water and that was based on how much water went to the area before. But farms could use all the water they needed. So developers just bought the land and grew lettuce on it for a couple years. Lettuce uses a lot of water... End result, more water was used (the opposite of the intention) and housing got that much more expensive 'cause sitting on it as farmland for a couple years got factored into the development costs.
In the medicaid system in CA they passed a law that they wouldn't give free health care (or something - maybe certain meds) to drug addicts. So psychologists who wanted them to get the free care just started diagnosing them as schizophrenic or with other mental illness so they could get the meds. Then their children in the foster/adoption system had the label that their biological mom was schizophrenic and people were afraid to adopt them.
Those are not related to immigration but it just seems that laws intended to control/manipulate people's behavior often backfire. You'd think there would be something we could do though. It seems
like national suicide to give our jobs out to folk from other countries.