The Constitutional slavery exception nobody talks about

The 13th Amendment abolished slavery. What follows the abolition, separated by the word “except,” has been generating litigation and constitutional argument for 60 years. Most Americans can’t identify it. Section 1 is 39 words and worth reading before the argument about it proceeds any further.

“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.”