The 13th amendment banned chattel slavery, but turbocharged penal slavery.

Deregulation in general and of the for profit prison industry in particular has made it so that there's more slaves in the US now than there ever was before the 13th was passed.

Granted, penal slavery is of course nowhere near as bad as chattel slavery was, but it's still slavery, which is morally repugnant barbary and outlawed in every civilized legal system i the world.

Go read it again; the word "except" is doing the heavy lifting here.