Missouri voters will go to the polls on Nov. 3 to decide whether to overturn a 2024 constitutional amendment that legalized abortion in the state. If Amendment 3 passes, Missouri would become the first state in the U.S. to use the ballot to undo voter-approved reproductive freedom protections, according to law professor Mary Ziegler.
The upcoming vote follows a historic 2024 election where nearly 52% of voters enshrined abortion rights in the state Constitution, striking down a near-total ban. However, Republican lawmakers had signaled a plan to reverse those results even before the 2024 vote occurred. Sen. Mary Elizabeth Coleman, a Republican from Arnold, stated at the time that people will be given an opportunity to vote again
.
Terms of the Proposed Ban
The proposed Amendment 3 would strike down the 2024 legalizations and outlaw nearly all abortions in Missouri. Under the new measure, the procedure would only be permitted in cases of rape and incest prior to 12 weeks of pregnancy, or during medical emergencies.
In an effort to attract more voters, lawmakers included language in the amendment that would place a constitutional ban on gender-affirming care for minors. While surgeries are already banned under a 2023 state law that does not expire, the current law banning hormone therapy and puberty blockers is set to expire next year.
Legislative Path and Public Opinion
The push for the Nov. 3 ballot reached a turning point in May 2025, when Missouri Senate Republicans ended a Democratic filibuster in a vote that placed the measure on the ballot. House Majority Leader Alex Riley, a Republican from Springfield, noted that the Republican majority is a pro-life majority
and sought to put a new question before the voters.
Recent data indicates the vote may be narrow. An August poll conducted by YouGov and Saint Louis University found that 44% of respondents opposed the measure, 43% supported it, and 13% remained undecided. This follows a period where abortion opponents argued that voters did not understand the measure they approved in 2024, as reported by the Kansas City Star.
