On Sunday night—the evening before the new school year begins in Texas—a federal judge in Fort Worth issued a nationwide injunction, preventing the Obama administration’s trans-friendly school guidelines from taking effect. The guidance, issued jointly by the Department of Education and Department of Justice, would have barred schools that receive federal funding from discriminating against trans and gender-nonconforming students. But U.S. District Judge Reed O’Connor blocked the new guidelines from taking effect, holding that the federal government had exceeded its legal authority—and that the policies would harm students who are forced to use the same bathroom as their trans peers.

O’Connor, a George W. Bush appointee, makes clear throughout his ruling that he did not approve of the administration’s new guidelines, which would have allowed trans students to use the bathroom and locker room that aligns with their gender identity. His decision includes a brief section alleging that the Obama administration promulgated its trans-friendly guidance too quickly under a federal law governing agency rulemaking. But the thrust of O’Connor’s ruling is much broader: The judge holds that Title IX’s ban on “sex discrimination” in federally funded schools may never legally be interpreted to protect “transgendered students.” (That’s the judge’s unfortunate phrasing.)

For O’Connor, the main problem here is an early Title IX rule allowing for “separate toilet, locker room, and shower facilities on the basis of sex.” Recently, the DOE had argued that this rule doesn’t actually address how it should apply “when a transgender student seeks to use those facilities.” So it issued clarifying guidance, declaring that while separate bathrooms are acceptable, schools may not use Title IX to discriminate against students on the basis of their gender identity. The DOE’s interpretation of “sex discrimination” to include gender nonconformity stretches all the way back to a 1989 Supreme Court case. But O’Connor held that “it cannot be disputed that the plain meaning of the term sex” as used in Title IX and its implementing regulations “meant the biological and anatomical differences between male and female students as determined at their birth.”

Of course, Title IX itself is silent on the precise contours of “sex discrimination,” as is that early rule allowing for separate bathroom facilities. Typically, when a law and its implementing regulations are ambiguous, the government must defer to the agency’s own interpretation, so long as it’s reasonable. Yet O’Connor works around this fundamental principle by holding that “sex discrimination” is not ambiguous at all. The judge asserts that Title IX and its early guidelines clearly intended to let schools draw “distinctions … based on the biological differences between male and female students.” In O’Connor’s view, Title IX did not acknowledge the existence of trans students—and that means the DOE is permanently prevented from interpreting Title IX in a manner that accommodates them.

O’Connor’s assertion that Title IX can never be used to proscribe discrimination against trans and gender-nonconforming students—simply because Congress didn’t mention them—is dubious for two reasons. First, the Supreme Court has explicitly stated that statutory prohibitions on sex discrimination may “go beyond the principal evil to cover reasonably comparable evils”—even when Congress did not explicitly intend for the law to cover those “comparable evils.” Second, the court has also formally accepted a theory of sex discrimination that encompasses gender nonconformity and sex stereotyping, the root of anti-trans discrimination. Myriad district and circuit courts have extended this principle to find that anti-trans discrimination itself may be a form of sex discrimination.

That leads to the biggest question raised by O’Connor’s ruling: Does he actually have the authority to enjoin the new guidance nationwide? O’Connor writes that states would be injured by the implementation of the guidelines and that schoolchildren would be harmed by having to share bathrooms with trans students. And Republican-appointed Texas judges infamously enjoy stretching their authority to block federal actions across the country, as the immigration reform battle proved. But O’Connor’s injunction is something new: A district judge purporting to halt the implementation of federal guidance in states where an appeals court has already approved the exact same guidance.* The U.S. Court of Appeals for the 4th Circuit held in April that the DOE’s trans-friendly guidelines were reasonable and legal. And other circuit courts have issued decisions in similar contexts that accept the theory of sex discrimination that O’Connor rejects. Does O’Connor believe he has the power to reverse the decision of a higher court outside of his circuit?

Perhaps he does, because O’Connor seems to have confused himself with a one-man Supreme Court. The judge also blocked the federal government from “asserting the guidelines carry weight in any litigation,” an extraordinarily dubious extension of his jurisdiction as a district judge. O’Connor frames his decision as a check on executive overreach, but the ruling itself reads like a king’s decree, forcing the federal government to comply with his own small-minded and idiosyncratic conception of sex. This ruling may well be overturned by the 5th Circuit or the Supreme Court, but O’Connor has already set a dangerous precedent. Texas has discovered that if you find the right judge in the right state, you can bring the federal government’s work to a grinding halt. Why even try to win national elections when conservative states can control the federal government through a handful of right-wing judges in the South?

*Update, August 23, 2016: Jonathan Adler argues in a National Review post that the 4th Circuit did not affirm the legality of “the exact same guidance” that O’Connor rejected. Technically, he is correct. The guidance at issue in O’Connor’s decision was a “Dear Colleague” letter issued jointly by the Department of Education and the Department of Justice issued in May of 2016. The interpretation at issue in the 4th Circuit decision was an opinion letter issued by the Department of Education’s Office for Civil Rights issued in January 2015. However, the conclusion of both letters was the same: Title IX’s ban on sex discrimination encompasses gender identity discrimination, including the exclusion of trans students from the appropriate bathrooms.