[lemma]

To add to what you wrote about the fine line, slavery as punishment is permitted by the 13th amendment:

Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction.

[nyrina]

Is there any way a normal person can give out a punishment for a crime, and let thereby take another person as an actual, lawful, slave?

[lemma]

No, but there are privately run, for-profit prisons....