Republicans across the country are ramping up efforts to pass laws that refuse to recognize transgender people, including by attempting to codify definitions of sex that legal advocates and biology experts say are unscientific and politically motivated.

At least 10 states have introduced or passed legislation to narrowly define what it means to be “male” or “female.” Such laws have myriad impacts for transgender people — from making it impossible to update birth certificates, driver’s licenses and state IDs with one’s correct gender marker, to barring people from using bathrooms that align with their gender identity.

“What they’re trying to do is excise transgender people from the protections of state code,” said Sharon Brett, an attorney at the ACLU of Kansas, referring to lawmakers in her state who passed a law last year that narrowly defines sex.

Such laws make it harder for transgender people to go anywhere where ID is required — airport security, banks, job applications, voting booths — and could make them even more vulnerable if dealing with police.

“If you are forced to carry ID documents that do not reflect how you live in the world, but rather reflect only the genitals you had when you were born, that essentially outs you as transgender to anyone you present your identification to in the normal course of business,” Brett said.

Republican lawmakers claim these laws provide necessary clarifications on the distinctions between sex and gender and will protect women and girls in locker rooms and bathrooms — even though there is no evidence suggesting that transgender people pose a risk to public safety. Trans and nonbinary teens are actually at greater risk of sexual assault when schools deny them access to locker rooms and bathrooms that match their gender identity, according to a 2019 study in the journal Pediatrics.

In early January, Missouri state Rep. Adam Schnelting (R) defended bills HB 2308 and HB 2309, which define sex as “the presence or absence of a reproductive system that produces, transports, and uses eggs or sperm for fertilization, regardless of any developmental or genetic anomaly or historical accident.” He insisted he wasn’t debating “whether the medical community is right or wrong,” and said he wanted to protect kids from people who take advantage of trans-inclusive policies. But when pressed by Democratic state Rep. Ashley Aune for any example of this nefarious behavior, Schnelting couldn’t name one.

“Predatory and violent behaviors targeting women and children, whom these bills are claiming to protect, are already criminalized and enforceable, without targeting a population that is itself most at risk of experiencing violence and harm,” said Zachary DuBois, an assistant professor of biological anthropology at the University of Oregon. DuBois helped co-author a statement from seven American biological associations condemning “legislation that is rooted in and maintains a rigid binary conceptions of sex and gender.”

‘Beyond Who Has Produced Eggs’

Not only do these laws put trans and gender-nonconforming people at greater risk of harassment and violence, but biology experts say the definitions the Republican lawmakers rely on — typically connected to chromosomes or reproductive organs — have little basis in science.

Utah Gov. Spencer J. Cox (R) on Tuesday signed a bill that bars transgender people from using bathrooms in schools and government buildings, and that defines “male” and “female” based on one’s reproductive system. Indiana is currently considering a bill that defines a “female” as someone “with a reproductive system that, but for a medically verifiable genetic disorder of sex development, at some point produces ova,” while a bill in Wyoming says a “female” is someone who produces ova “and/or exhibits XX chromosomes and does not exhibit a Y chromosome.”

But sex is not defined solely by one’s genitals or reproductive capacity, sex and gender researchers told HuffPost. Instead, scientists understand sex to include a number of different biological phenomena from the production and size of one’s eggs and sperm, hormones, genitals, brains, secondary sex characteristics, and internal sex characteristics like uteruses, fallopian tubes and testes — and, increasingly, gender expression and identity. (Gender is a social and cultural construct that is related to our biological differences but rooted in how we perceive ourselves in the world.)

“You only need to leave your house to understand the wide array of gender and sex diversity beyond things like who has produced eggs versus who has produced sperm,” Sari van Anders, a professor of psychology, gender studies and neuroscience at Queen’s University, told HuffPost.

Legislative attempts to impose restrictions based on sex assigned at birth have become a focus of the GOP in recent years. Former President Donald Trump ignited efforts to exclude transgender people from policies and sex discrimination protections as a direct backlash to the decade of progressive Obama-era decisions that protected gender identity and expression. Toward the end of Trump’s time in office, however, the Supreme Court expanded sex discrimination protections to include gender identity and sexual orientation.

The current wave of legislation that explicitly defines “biological sex” has only started to emerge within the last year — and it comes with unprecedented and broad policy implications.

Advocates say the slate of sex definition bills has the potential to cause wide-reaching harm. The bills encourage people to police each other’s bodies, which can endanger transgender, gender-nonconforming and cisgender people alike. There have been numerous examples of both cisgender women and trans women being harassed in bathrooms, and of parents and school athletic associations questioning a student’s gender.

These bills also help legitimize other anti-LGBTQ+ legislation that targets the ability to receive gender-affirming care, participation in sports, and access to restrooms. Many bills attach specific definitions of sex to restrictions on identifying documents or bathroom bills. Florida’s HB 1233 goes as far as to require individuals to sign an “affidavit” certifying their “biological sex.”

Separately last week, transgender Floridians lost the ability to change the sex on their driver’s licenses, after the state’s Department of Highway Safety and Motor Vehicles quietly issued a memo that warned “misrepresenting one’s gender, understood as sex, on a driver license constitutes fraud.”

Some states that have already adopted legal definitions of sex are beginning to see a ripple effect of the new policies hurting and encouraging discrimination against trans residents.

Last year, Oklahoma Gov. Kevin Stitt (R) signed a “Women’s Bill of Rights” executive order, which was modeled after legislation inspired by a conservative Christian group that had twice failed in the state legislature. The executive order defines “female” and “male” by a person’s sex assigned at birth, and directed all state agencies and public schools to use this definition when collecting vital statistics and to require sex-segregated facilities for girls and boys. It also immediately barred trans Oklahomans from updating their gender markers on their IDs.

A few months later, Ryan Walters, an anti-“woke” crusader who oversees the public schools in Oklahoma, took the policy a step further. He said he would only approve textbooks that use the same definition of sex that was found in the “Women’s Bill of Rights.” Several textbook publishers have already withdrawn from the state following Walters’ conservative push.

Trans people in Kansas, which passed a law defining biological sex last year, say they’ve been discriminated against in their jobs or at school, according to Brett, the ACLU lawyer.

“It’s sowing quite a bit of confusion and is being used both by government agencies and individual actors to discriminate against trans people, which is really unfortunate and harmful,” Brett said.

No matter how conservatives try to define sex and gender to fit with their political goals, DuBois said, we cannot ignore the fact that transgender, gender-nonconforming people, and intersex people are still here — and deserving of equal protection under the law.

“You can’t legislate us away, you can’t policy us away,” DuBois said. “You can try to exclude us from public space to reduce our access to freedoms that other people have. But we exist.”

Culture Of Policing

Under Barack Obama, the U.S. Departments of Justice and Education issued guidance to public schools around Title IX and Title VII, protecting transgender students’ rights to use bathrooms that align with their gender identity and prohibiting sex discrimination based on transgender status.

Trump rolled back those protections, including those against sexual harassment, and tried to establish a narrow legal definition of gender as a biological and immutable condition from birth. During his current presidential campaign, he has signaled he would only expand his anti-LGBTQ agenda if elected to a second term.

Advocates say it doesn’t really matter if bills defining sex even make it out of state legislatures. The very attempt to erase transgender people from the law has already caused enormous harm. People are losing access to life-saving medical care and other rights, as well as facing increased discrimination in their day-to-day lives. Last winter, a trans boy in Texas, for example, was briefly kicked out of his school play after his school enacted a new policy of casting actors based on their sex assigned at birth.

Van Anders sees this moment as one that parallels anti-gay history in the U.S. She used to teach her class about how police would use a “three-article rule” to arrest LGBTQ+ people for cross-dressing if they weren’t wearing clothes that matched the stereotypes associated with their sex assigned at birth. She worries that this kind legislation will give rise to a similar sort of surveillance.

“This current political moment shows some of the same absurdity of policing people’s gender expressions, their bodies and their identities,” van Anders said. “It used to be focused on erasing and shaming people who were seeming to be lesbian or gay … but we see similar tactics being used a century apart.”