WILLIAM BRANGHAM:

This ruling is the second setback in recent weeks for transgender advocates. Earlier this month, the Supreme Court said a Virginia school board could block a transgender student from using the boys bathroom while the higher court decides if it will take up these broader case.

Yesterday's decision is the first to say that the Obama administration's directive could be blocked nationwide. Those directives instructed school districts to allow trans students to use the bathroom of their choice. Texas is one of 13 states challenging the constitutionality of the directive.

In this case, the judge wrote that the administration had exceeded its authority under Title IX, the 1970s-era law banning sex discrimination in schools.

To help us wade through the meaning of all this, I'm joined now by Evie Blad, who is the Education Week reporter who's been covering this story.

So, Evie, what does this ruling say, and how significant is this?