Suppose all non-US-citizens working in the US had to be paid at least at the 60th percentile of what US citizens earn in their job description. They can come to the US and be an engineer or construction worker, but they can't undercut wages. And the penalty for underpaying immigrants is simply that they get their back wages plus interest.
Immigration enforcement would concentrate on employers, not migrants, and they wouldn't risk deportation if they reported exploitation.
If there were no market for exploited employees, if employers who tried to exploit people knew their immigrant employees could simply report them, get back wages, and stay in the US, I think you'd see an end to outrage over migrants who are coming due to desperate situations in their home countries. And there'd be one less issue for the GOP to manipulate voters over.
@AlphaCentauri our entire system is based on exploitation of resources, including Human Resources.