A group of Democratic lawmakers has reintroduced a joint resolution to negate a clause in the 13th Amendment of the Constitution that permits slavery or involuntary servitude "as a punishment for crime."

The "Abolition Amendment" was introduced on Wednesday ahead of Juneteenth -- the national holiday commemorating the end of slavery -- by Sen. Jeff Merkley of Oregon, Sen. Cory Booker of New Jersey and Rep. Nikema Williams of Georgia.

The 13th Amendment presently says, "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." The new resolution would clarify: ''Neither slavery nor involuntary servitude may be imposed as a punishment for a crime.''

The resolution would not seek to "interfere with opportunities for incarcerated people to consent to work," its sponsors said.

It's no easy task to amend the Constitution -- the resolution would require a two-thirds vote in both houses of Congress before it is sent to the states, where at least 38 legislatures would need to approve it for ratification -- and the effort to erase the slavery exception has failed in previous congressional sessions.

But advocates are encouraged by recent state-level efforts to amend their constitutions to remove the exception.

"The reality of that narrow exception is that it's impacted millions of people because slavery is still very much legal as criminal punishment. But I think at the root of it, we really are sort of centered on this idea that slavery is always wrong. There is no circumstance under which it is OK to enslave someone," said Bianca Tylek, the executive director of Worth Rises, a nonprofit that is campaigning to negate the clause from the 13th Amendment.

Those pushing the legislation told CNN that most Americans don't realize the "loophole" in the 13th Amendment. In a news release, they said that the "slavery clause" led to higher rates of arrests among Black Americans for "minor crimes, like loitering or vagrancy, codified in 'Black Codes'" throughout the Jim Crow era.

The resolution's sponsors said the clause incentivized "minor crime convictions and drove the over-incarceration of Black Americans on infamous prison plantations like Parchman in Mississippi and Angola in Louisiana."

"So, anyone who wants to be in a work program that is currently incarcerated, this would not change that," Williams told CNN. "This would not force any level of payment because they're not being forced into these programs. But we absolutely need to live up to what our country sees that we stand for. And in the exception for slavery once and for all."

Asked by CNN if the latest effort will garner bipartisan support, Merkley said, "There's been a sense that this is really something that needs to be fixed. But there isn't kind of the urgency of like a debt ceiling problem or a health care bill or something of that nature."

"To me, this is urgent. It's unacceptable that our Constitution allows slavery. It's way past time to remedy this clause," he added.

The movement to end the exception is also taking place on a statewide level, as the caveat is included in some state constitutions.

In November, voters in Alabama, Vermont, Oregon and Tennessee approved a measure to rid the punishment clause once and for all, while a similar measure failed in Louisiana.

Merkley told CNN that the statewide efforts give "legitimacy to the conversation about expunging it from the 13th Amendment."