Missouri voters on Tuesday supported a constitutional amendment that creates several barriers for lawmakers seeking to modify or overturn citizen-backed laws and amendments.
After getting roughly 60% of the vote from across the state, backers of Amendment 6 celebrated their victory Tuesday night at the Sheet Metal Workers Union Hall in St. Louis.
"Welcome to the first night of being able to feel safe from the legislature overturning the will of the voters of Missouri," said Missouri AFL-CIO President Jake Hummel.
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Amendment 6's passage establishes several new policies aimed at bolstering Missourians' right to the initiative petition process.
The amendment requires a minimum 80% vote in the Missouri Senate and House to change or repeal a citizen-led and approved statute or constitutional amendment.
Even if that threshold is met, the proposed changes then must go on the ballot for Missourians to decide.
"Voters aren't stupid," Hummel said. "They know what they're looking at, they know the amendments they're passing, and they're fed up."
While changes to approved constitutional amendments already needed additional voter approval, the same did not apply to statute changes.
Previously, lawmakers were able to amend or even repeal statute changes proposed and approved through the citizen initiative petition process.
The most recent example was in 2025, when the Republican-led legislature repealed a portion of a proposition that required employers to implement a paid sick leave policy.
Proponents of the amendment said it better protects voter-approved measures. Opponents said it makes it nearly impossible for lawmakers to make possibly needed changes to policies.
"It's also very troubling that this generation will essentially be locking future generations into everything that's been passed in the last 10 years and everything that'll be passed going forward," said Missouri Attorney General Catherine Hanaway. "It's the most regressive overturning of the will of the people, as reflected in who they've sent to the legislature, than I could possibly imagine."
Support for Amendment 6 comes nearly three months after Missourians rejected an amendment that would have made it much harder to change the state constitution.
That was Amendment 4, with 80% voting no. It would have required any constitutional amendment brought forward through the citizen initiative process to pass in each of Missouri's eight congressional districts.
Amendment 6 ensures that future efforts from lawmakers to make it harder to amend voter-backed state laws or constitutional amendments face an extremely uphill battle.
The amendment enshrines the current signature and voter requirements for proposed statute changes and constitutional amendments.
It prohibits the legislature from passing any policy that would weaken citizen initiative or referendum powers.
An example would be passing a law requiring gathered signatures to be written only in blue ink.
Additionally, the amendment contains new requirements regarding ballot summaries for proposed statutes and amendments. It states that ballot summaries, including summary statements and fiscal notes, "shall be clear, unbiased, fair, accurate and easy to understand."
The outcome Tuesday is likely to be challenged in court.
One section that could be scrutinized is a portion of the amendment that retroactively applies the newer standard of amending policies to any citizen-backed laws or amendments since 2010.
Benjamin Singer, who co-founded the group Respect Missouri Voters that helped get Amendment 6 on the ballot, said that while he expects lawsuits, he's confident that the proposal will withstand legal scrutiny.
"We vetted this through more attorneys than I would wish was the case, and nobody thinks that there are constitutional problems with this," Singer said. "Obviously, the Missouri Supreme Court made clear unanimously, with an opinion from their most conservative member, that this belongs on the ballot, and the politicians need to stop playing games with the people's initiative process."
Hummel said many labor unions were energized to push Amendment 6 across the finish line, because it could make it difficult for the legislature to resurrect "right to work." Voters repealed that law in 2018 through the referendum process. And if Amendment 6 is upheld, 80% of the legislature would need to vote affirmatively to put that plan on the ballot again.
"The beauty about this is that if there is something that is truly problematic, it's going to force a compromise between the two parties, and then it's still going to take a vote of the people," Hummel said. "So, if it is a real issue that needs to be changed, then you're going to have to forge a compromise to do it, and that's just good public policy all the way around."
This story has been updated with comments from supporters and opponents.
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