Four states approve ballot measures officially banning slavery under all circumstances

Multiple states officially outlawed slavery through ballot referendums on Tuesday.

Wait, slavery is legal?

The 13th Amendment to the U.S. Constitution, which outlaws slavery, does not actually prohibit the practice under all circumstances.

The one exception is that slavery can be imposed, according to the amendment, "as a punishment for crime whereof the party shall have been duly convicted."

Because of the wording, prisoners are often exploited for cheap labor. Thus, in recent years, criminal justice reform advocates have pushed for states to amend their constitutions to ban the practice. Colorado became the first state to do so in 2018.

What happened on Tuesday?

Voters in five states — Alabama, Oregon, Tennessee, Vermont, and Louisiana — had the opportunity to approve amendments to their state constitutions that would ban the practice of prisoner slave labor.

Tennessee's proposal, for instance, read, "Slavery and involuntary servitude are forever prohibited. Nothing in this section shall prohibit an inmate from working when the inmate has been duly convicted of a crime."

But only four of those states — Alabama, Oregon, Tennessee, Vermont — approved the measures, the Associated Press reported.

The AP explained why voters in Louisiana rejected theirs:

In Louisiana, a former slave-holding state, voters rejected a ballot question known as Amendment 7 that asked whether they supported a constitutional amendment to prohibit the use of involuntary servitude in the criminal justice system. Ahead of Election Day, state Rep. Edmond Jordan, a Democrat from Baton Rouge and author of the amendment, reportedly asked voters to reject the measure because its wording on the ballot differed from his proposal.

After Tuesday's results, more than a dozen states will still have language in their state constitutions permitting slavery or involuntary servitude for prisoners.

Last year, Sen. Jeff Merkley (D-Ore.) and Rep. Nikema Williams (D-Ga.) reintroduced legislation that would amend the Constitution to declare, "Neither slavery nor involuntary servitude may be imposed as a punishment for a crime."

Congress has not approved the amendment. If or when two-thirds of Congress does, the amendment would require three-fourths of states to ratify it.