The Trump administration has made it clear that it won’t protect transgender students from discrimination: On Wednesday, it sent out a letter officially revoking an Obama-era guidance protecting trans students in federally funded public schools.

The decision upholds a promise President Donald Trump made on the campaign trail, but comes as a major blow to LGBTQ groups who over the past few weeks pleaded with the administration to keep the guidance in place. And it means that trans students, who endure disproportionate levels of bullying and discrimination in public schools, and their parents will no longer be able to turn to the guidance for official support.

“What could possibly motivate a blind and cruel attack on young children like this?” asked Chad Griffin, president of HRC, an LGBTQ advocacy group. “These transgender students simply want to go to school in the morning without fear of discrimination or harassment. The consequences of this decision will no doubt be heartbreaking.”

A few months before Trump was elected president, the Obama administration sent out a legally nonbinding guidance to federally funded schools arguing that trans students are protected by existing federal civil rights law. So, the administration said, schools should respect trans students’ rights, including their right to use the bathrooms and locker rooms that align with their gender identity.

The Obama administration cited Title IX, which prohibits sex discrimination in schools. It argued that anti-trans discrimination is a form of sex discrimination, because discrimination against trans people is rooted in stereotypes and prejudices of what people should be like based on the sex they were assigned at birth.

But Trump said the guidance, even though it was not legally binding, was an example of federal overreach and a misinterpretation of federal law, and he vowed to undo it once he was elected. A federal court had already placed an injunction on the guidance last year, but the Trump administration’s moves have sealed its demise.

Trump’s decision apparently caused some in-fighting within the administration, the New York Times reported. Since the guidance dealt with schools, it required a sign-off from Education Secretary Betsy DeVos, who was apparently uncomfortable leaving trans students unprotected. DeVos’s pushback caused her to clash with Trump and Attorney General Jeff Sessions, both of whom have long wanted the guidance revoked. Faced with the decision to disobey the president or resign, she ultimately played along.

The letter revoking the guidance, however, includes a small glimmer of hope, reportedly on DeVos’s insistence: It says schools must create a safe environment for all students, including, it notes, “LGBT students.”

“All schools must ensure that all students, including LGBT students, are able to learn and thrive in a safe environment,” the letter states. “The Department of Education Office for Civil Rights will continue its duty under law to hear all claims of discrimination and will explore every appropriate opportunity to protect all students and to encourage civility in our classrooms.”

Exactly how this will be enforced remains unclear, given that the administration now has made it official that it doesn’t consider Title IX to officially protect trans students.

The guidance is important not just because of what it says about trans students in schools, but what it says for federal civil rights laws and trans people more broadly. Through this guidance and other actions, the Obama administration took a widely welcoming interpretation of federal civil rights laws to include trans people. With the Trump administration’s decision to ditch the guidance, it’s signaling that it will take a much narrower view of federal civil rights law — one that leaves trans people behind, even as they lack explicit civil rights protections in most of the country.

The Obama administration’s guidance was trying to clarify a key dispute in civil rights law

Under most states’ laws and federal law, trans people are not explicitly protected from discrimination in the workplace, housing, public accommodations, and schools. This means that a trans person can be fired, evicted, kicked out of a business, or denied the correct bathroom facility just because an employer, landlord, business owner, or school principal doesn’t abide by or acknowledge the trans person’s gender identity.

The Obama administration, under the urging of LGBTQ groups and a federal agency that focuses on workplace discrimination, adopted a different view of the law. It argued that federal civil rights laws do protect trans people in the workplace, housing, and schools.

The argument: In these settings, federal civil rights laws already prohibit sex discrimination, which should cover trans people because discrimination based on gender identity — and against trans people — is fundamentally rooted in expectations of what people of certain sexes assigned at birth should be like.

So the Obama administration sent out guidance to public schools making this more formal policy, establishing guidelines that schools should try to follow. But until courts validate the guidance, it’s really a legally nonbinding set of guidelines.

Yet if courts approved of the Obama administration’s interpretation of federal civil rights laws, they could effectively expand existing civil rights protections that explicitly ban discrimination based on race and sex, among other traits, to specifically include gender identity. That could, in turn, bleed over to federal civil rights laws beyond Title IX and education — such as the Civil Rights Act’s protections in the workplace and the Fair Housing Act’s provisions for housing. (A case dealing with these issues is in front of the Supreme Court right now.)

But conservatives, including those in the Trump administration, see the trans-inclusive view as a misinterpretation of federal laws. They argue that the authors of civil rights laws, which go back to the 1960s and ’70s, never intended to include trans people in sex discrimination bans, so trans people shouldn’t be protected under the statutes.

Trump has also said that this issue should be left to the states, which would effectively let conservative states continue to allow discrimination against trans kids in schools.

Much of the debate has been fueled by a big political hurdle: bathrooms. Under the trans-friendly interpretation of the law, school officials are discriminating — and violating civil rights laws — if trans students are blocked from using a bathroom or locker room for their gender identity. After all, forcing trans people to use the facility that doesn’t align with their gender identity acts as a reminder that society still isn’t completely willing to accept them and their identities, even if trans people pose no danger to anyone else.

This has become a major flashpoint in the LGBTQ rights debate — taking off last year when North Carolina passed HB2, which prohibits trans people in the state from using the bathrooms and locker rooms that align with their gender identity in schools and government buildings. When the Obama administration sued North Carolina and sent out its guidance to schools across the country, the bathroom issue became an even bigger deal — even though the anti-trans talking point that sparked it is based on a huge myth.

The big counterargument to the guidance is based on a myth

Underlying this entire issue is a big myth about trans people, nondiscrimination laws, and bathrooms.

According to supporters of North Carolina’s HB2 and opponents of the Obama administration’s guidance, letting trans people use the bathroom for their gender identity would pose a public safety risk. They claim that if trans people can use the bathroom that aligns with their gender identity, men will take advantage of such policies to disguise themselves as trans women and sneak into women’s bathrooms or locker rooms to sexually assault or harass women.

Some religious conservatives have latched onto this myth to oppose laws that ban discrimination based on sexual orientation and gender identity in the workplace, housing, public accommodations, and education. In Houston, for example, voters struck down a local nondiscrimination law after opponents of the ordinance trumpeted the bathroom myth. And North Carolina’s law came after Charlotte added sexual orientation and gender identity to its nondiscrimination protections for public accommodations. (More on all of that history in Vox's broader explainer.)

This is also the argument that Texas has repeatedly cited to defend its position as it filed a lawsuit with several other states against the Obama administration’s guidance.

But even if trans people are allowed to use the bathroom for their gender identity, sexual assault remains illegal. So a legal deterrent to deviant behavior already exists.

There’s also no evidence that nondiscrimination laws — and other policies that also let trans people use the bathroom for their gender identity — lead to sexual assault in bathrooms and locker rooms. In two investigations, Media Matters confirmed with experts and officials in 12 states and 17 school districts with protections for trans people that they had no increases in sex crimes after they enacted their policies.

Conservatives usually counter that there are examples of men sneaking into women's bathrooms to attack women. But as PolitiFact reported, none of the examples cited in the US happened after a city or state passed a nondiscrimination law or otherwise let trans people use the bathroom or locker room for their gender identity. Instead, these seem to be examples of men doing awful things regardless of the law — which has, unfortunately, happened since the beginning of civilization.

One example is a case in Toronto, Canada, which now has a nondiscrimination law, in which a man disguised himself as a woman and attacked women in shelters. But the attacks happened months before Ontario (Toronto's province) protected trans people in a nondiscrimination law. So the law couldn't have been the cause.

Still, the myth has persisted, trickling up in some way or another all the way to legal battles over federal laws. And it’s a big reason the Trump administration has killed off protections for trans students in public schools.