“We had accepted that federal law would preempt state law, that it would be preposterous that one federal judge in one district in Texas—or in any other state—would be able to affect the availability of a drug that had had FDA approval for 20 years,” says Khiara M. Bridges, a professor of law at the University of California, Berkeley. “Now the things that we thought we knew about the relationship between federal law and state law, and the FDA’s ability to regulate, have been called into question.”