After the Fourth Circuit Court of Appeals rejected a request Tuesday to reconsider a previous ruling affirming the rights of a Virginia transgender student, Gov. Pat McCrory's defense of HB2 has a hit a major road block.

The intermingling of the two cases in question—the pivotal Virginia case ( G.G. v. Gloucester County School Board ) decided in favor of transgender student Gavin Grimm, and McCrory’s HB2 defense, McCrory v. United States—charts a course for the future demise of HB2’s bathroom provision.

Here are the basic facts governing McCrory’s case in defense of HB2:

1) North Carolina falls within the Fourth Circuit’s jurisdiction, which means the Virginia ruling siding with a transgender student’s right to use their bathroom of choice applies to the Tar Heel State.

2) Grimm’s case was decided on the basis of sex discrimination prohibitions included in Title IX of the Education Amendments of 1972, a federal law that McCrory's lawsuit against the federal government fails to address, writes Ian Millhiser.

The Justice Department’s letter concludes that HB2 violates three separate federal laws, Title VII, the Violence Against Women Reauthorization Act, and Title IX of the Education Amendments of 1972. McCrory’s complaint claims that the state is not violating the first of these two laws, but it is conspicuously silent regarding Title IX. [...] McCrory’s silence regarding Title IX may be an acknowledgement that any effort to defend his states actions under Title IX is doomed.

3. Now that the Fourth Circuit has declined to rehear G.G., the only other avenue for reversal of the ruling is the Supreme Court, which seems unlikely to overturn it—if the justices even decide to take up the question.