Yes, you could stop it at the point of demand. I remember AZ implemented eVerify or some such, don’t know what effect or loopholes it had. In Texas:

  Whenever Texas politicians threaten to pass laws that would make it harder for businesses to employ undocumented workers, phones in the Capitol start ringing. Stuck with the need to show their base that they’re cracking down on migrants, politicians, including Abbott, have instead found a middle ground: They keep up their bombast regarding the border, but they avoid stringing any razor wire between undocumented immigrants and jobs in the state’s interior.

https://www.texasmonthly.com/news-politics/border-crisis-tex...