[a3n]

Coincidentally, there's a measure on the Colorado ballot this year (I voted for it), that removes a state constitutional exception to allow slavery for punishment of convicted criminals.

Slavery, in the Colorado and many other state constitutions, is explicitly forbidden. Colorado, at least, allows an exception for convicted criminals.

I can't believe it's 2016 and I find myself having to say "yup, slavery is bad, let's not do that."

[JoeAltmaier]

Convicts have most of their rights abrogated. Its essentially slavery however you label it? Just like killing folks for high crimes is not 'murder', imprisoning folks and making them work for their keep is not 'slavery'.

[rhizome]

Killing people for high crimes is not murder, but it is listed as homicide on their death certificate.

I'm not sure of the distinction you're making, but you may be confused about categories of slavery, of which chattel slavery (what the US had until 1865) is only one. You may be thinking of indentured servitude, but even that doesn't map precisely to prison labor.

[dragonwriter]

Yes, it is slavery, which is why in order to not prohibit it, the 13th Amendment include an express exception for criminal punishment when otherwise abolishing slavery.

[a3n]

Here's 100 jobs in this building. It's 100 jobs that have to be done, that people will pay for the result. They aren't great jobs, say maybe $13/hour, but they're jobs.

Except no, we're not going to let 100 people have those $13/hour jobs. Instead, we're going to have 100 prisoners do those jobs for free, or next to nothing.

Sorry prisoner slaves. Sorry free citizens.

EDIT: And oh, we also have to pay guards to watch them do those jobs. So not free labor, not really.