This is exactly what I've been thinking lately. And on top of already existing laws, make new ones that criminalize currently normal things. Hell, the South enacted new laws after slavery ended and only applied them against Black Americans. Why stop there, why not increase penalties for certain crimes from misdemeanors to felonies and make 3 felony convictions mean a life sentence?
The only part I disagree with is the for profit prisons part. 8% of prisoners are in private prisons which is 8% too many, but 92% are in publicly funded and operated prisons. And those publicly operated prisons sell the services of their trapped slave labor for so many more things than stamping license plates or road work. Not only do they fight fires and clean up after natural disasters, they also make kit (armor, helmets) for the armed forces, they pick crops, they manufacture white goods (washing machines, refrigerators)(I can't find a link specifically mentioning appliances and I'll update this it I find one), and so much more. Shoot, some cities' budgets would be blown up if not for the availability of publicly held prison slaves.
This isn't exactly what the previous comment was talking about, but it's similar. https://www.theguardian.com/world/2011/oct/14/alabama-immigration-law-workers and there's something similar going on Florida too https://www.npr.org/2024/04/26/1242236604/florida-economy-immigration-businesses-workers-undocumented
These are my go-to articles anytime the subject of undocumented workers comes up. Personally, I think we would go back to the old model. If I remember correctly, the 1930s was when immigration started to be severely restricted; but, before that, temporary workers would come up for a season of employment and then go back home. All of it was done legally. It wasn't until immigration restrictions were enacted that there was an incentive to stay and move their families into the US.