Oh hey, we've played this game before. And it went as poorly as informed people expected. More than once, if you can believe it.
I believe, based on absolutely nothing, that if mass deportations happen, then there'll be a change in the farming labor force. No one will do the work at current wages and the owners will resist raising wages. The vacuum will be filled by prison slaves because they don't get a choice and they get paid pennies per hour.
I don't know what the restrictions are on using enslaved prisoners, but if there are any, they'll be removed and the process to acquire them streamlined. That alongside enacting draconian laws to imprison and enslave even more people should be enough to offset the loss of migrant labor. I hope I'm wrong.
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.