(CNN) Congressional Democrats want to amend a section of the 13th Amendment, which abolished slavery, to end what they refer to as another form of slavery -- forced prison labor.
Sen. Jeff Merkley of Oregon and Rep. William Lacy Clay of Missouri introduced a joint resolution this week that would remove the 13th Amendment's "punishment clause," or language that excepted convicted prisoners from the ban on slavery and involuntary servitude.
"Our 'Abolition Amendment' seeks to finish the job that President Lincoln started by ending the punishment clause in the 13th Amendment to eliminate the dehumanizing and discriminatory forced labor of prisoners for profit that has been used to drive the over-incarceration of African Americans since the end of the Civil War," Clay said in a statement.
When it was ratified in 1865, the 13th Amendment made slavery illegal -- "except as punishment for a crime of which one has been convicted," the amendment's text reads.
The "Abolition Amendment" would strike that clause from the 13th Amendment and end forced labor among prisoners, the congressmen said. Work programs for prisoners would continue on a voluntary basis.
Avi Soifer, a professor and former Dean of the University of Hawaii at Manoa's Richardson School of Law, told CNN that it's unlikely that efforts to amend the constitutional amendment will succeed.
It may be more beneficial to institute "partial remedies," he said, like the federal statute that outlaws voluntary and involuntary peonage, a type of servitude by which people who owe debts work until those debts are paid.
"It thus could have immediate relevance in efforts to address the terrible ways that we now treat prisoners and those jailed because they are unable to make bail," said Soifer, a 13th Amendment expert.
Merkley and Clay, in their release, call the "punishment clause" in the 13th Amendment "indisputably racist in origin and in impact."
Because the South relied on slave labor for its economy in the 19th century, that line in the amendment was used as a loophole to continue the forced labor of Black Americans who were imprisoned, according to the non-profit Equal Justice Initiative, which works to end mass incarceration.
The "punishment clause" led to higher rates of arrests among Black Americans throughout the Jim Crow era to the War on Drugs in the 1980s, the congressmen said in the release, by effectively creating a "financial incentive for mass incarceration" -- renting forced labor of disproportionately Black prisoners.
Prison labor is a lucrative industry. NPR reported in July that as of the last federal count in 2005, over 1.5 million prisoners were working. UNICOR, a federal prison labor program, generates over $500 million in revenue every year, NPR reported.
But the practice exploits prison laborers, its opponents say. Many states, mostly in the South, don't pay inmates for working regular prison jobs, according to the Prison Policy institute, and the high end of their wages for regular prison jobs rarely exceed $1.
Sens. Bernie Sanders and Ed Markey, among others, have cosponsored the amendment, which has earned the support of social justice organizations like Human Rights Watch, Amnesty International and Color of Change.