Four states vote Tuesday on ballot measures that could reshape girls' and women's sports

On Tuesday, voters in four states decide whether to rewrite the rules for who competes in girls' and women's sports. The measures are on the ballots in Arizona, Colorado, Nebraska and Washington, and in some cases they also reach into who may use school locker rooms.

The four states start from different places. Arizona and Nebraska already have laws restricting biological males from female sports, so a yes vote there would expand or strengthen what is on the books. Washington and Colorado have no such statewide restrictions. If their measures pass, both states, traditionally Democratic, would establish statewide sex-based rules for school sports for the first time.

In Washington, Initiative 638 would bar students defined as biologically male from girls' K-12 interscholastic sports. Girls seeking to play would need documentation from a healthcare professional verifying biological sex based on reproductive anatomy, genetic makeup, or normal endogenously produced testosterone levels. Under current eligibility rules, athletes can compete based on gender identity, which allowed a boy in Camas to switch to the girls' team mid-season earlier this year. A no vote keeps those rules. Opponents, including No Hate in Washington State, say the initiative discriminates against transgender students and could expose girls to invasive genital examinations. Proponents call that fearmongering, saying sex can be verified through a routine sports physical or a cheek swab for DNA. Polymarket put the chance of passage at 64% at the time of writing.

Colorado's Proposition 134 is broader in reach. It would set sex-based participation requirements from K-12 through college, across public, charter and private schools and colleges and universities, covering interscholastic and intramural athletics, including school-sponsored club sports. Athletes would generally compete on teams matching their biological sex, with exceptions for coed sports and for girls joining boys' teams when no girls' team exists. The measure defines females as people whose reproductive system is organized around producing ova, and males around producing sperm. Unlike Washington's initiative, it requires no doctor's note or exam; schools would write their own eligibility policies, and the state education commissioner could act against districts that intentionally refuse to comply. Planned Parenthood and other opponents call it government overreach that risks invasive gender checks. Jennifer Sey, founder of XX-XY Athletics and chair of the campaign backing it, notes that 27 states already restrict biological males in girls' sports and argues the invasive exams opponents describe are not happening there. Polymarket put passage at 55%.

Arizona's Proposition 318 builds on existing public school rules by extending restrictions to private schools and to athletic associations, including those overseeing youth and college sports. It would also require schools and associations to limit access to restrooms, locker rooms and other private athletic spaces based on the sex on an original birth certificate. Athletes could sue schools and associations that knowingly violate the law. Coed team protections would remain, and girls would not be categorically barred from boys' teams. The ACLU and other civil rights groups say it singles out transgender students, could lead to intrusive questioning of girls, and exposes schools to costly lawsuits. Supporters say it closes loopholes, protects privacy and safety, and sets consistent rules. Polymarket put passage at 82%.

Nebraska's Initiative 442 would amend the state constitution to bar biological males from girls' and women's school sports from K-12 through college. Schools would designate teams as male, female or coed, with female teams reserved for biological females. It covers public schools and colleges, plus private institutions whose teams play public schools. Gov. Jim Pillen signed the Stand With Women Act in June 2025, so a law already exists; the amendment would make it harder for future lawmakers to overturn. OutNebraska and the Fairness for All campaign call it discriminatory and unnecessary, noting that transgender athletes are a tiny share of the population. The Fairness for Girls campaign argues that boys competing against girls raises safety concerns and can cost girls medals, advancement and scholarships. No Polymarket prediction was found for Nebraska.

The results will show how voters weigh these arguments in four different political settings. If Washington's and Colorado's measures pass, the open questions will be how verification works in practice and, in Arizona, how often the new lawsuit provision is used.