Texas federal Judge Matthew Kacsmaryk has halted the U.S. Food and Drug Administration’s approval of mifepristone, one of the two drugs used in the agency’s approved regimen for medication abortion, setting off what is sure to be a host of appeals that could take years to sort out.

In his 67-page opinion, Kacsmaryk ruled that the drug was improperly approved in violation of federal law.

The judge gave the federal government seven days to appeal, so the ruling does not immediately take effect.

While this case is unprecedented, Judge Kacsmaryk’s ruling wasn’t surprising. As previously reported, Judge Kacsmaryk has long been open about his hostility to abortion rights. He has written critically about the 1973 Roe v. Wade ruling and has consistently backed conservative causes, including as a former staff attorney for the First Liberty Institute, a Plano-based nonprofit law firm that specializes in “religious liberty” cases (”religious,” of course, meaning the Christian Right).

Read more: The blueprint for the anti-abortion movement’s next fight

In a hearing on March 15 that lasted more than four hours, Kacsmaryk quizzed the plaintiffs from the conservative legal firm Alliance Defending Freedom about how he could write a decision that uses his authority to unilaterally withdraw FDA approval for mifepristone and whether the Comstock Act, a little-enforced 1800s-era obscenity law that prohibits sending materials “for any indecent or immoral use” through the Postal Service.

As Mary Ziegler, a legal historian and law professor at the University of California Davis, put it in a previous interview: “If you were picking any judge, at least in the United States, to make this kind of argument in front of, you would pick him.” Indeed, the reason the case was filed in Amarillo, Texas, was to virtually guarantee that Judge Kacsmaryk would preside.

Mifepristone has been on the market for more than 20 years.

If the FDA appeals the Texas judge, it will go before the U.S. 5th Circuit Court of Appeals, the most ideologically conservative in the nation, which also previously heard the Dobbs case out of Mississippi, which overturned Roe last year.

This story is developing. We’ll update it as we find out more.