In October 2013, two investigators from the Texas Medical Board arrived at Dr. Joseph Zadeh’s medical practice in suburban Dallas with an administrative subpoena for the medical records of more than a dozen patients, joined by two DEA agents. When a medical assistant told them that she would need to contact a lawyer first, they said Zadeh’s license was at risk if she didn’t comply immediately. She backed down, and they rooted through Zadeh’s patient files for evidence of wrongdoing—all without a proper search warrant.

Zadeh and an unnamed patient thus sued the board in federal court. The Fifth Circuit Court of Appeals agreed that the board had violated Zadeh’s rights with the warrantless search. But it ruled against him nonetheless. The court found that under the Supreme Court’s precedents on qualified immunity, a legal privilege for certain types of government officials, the violation of Zadeh’s rights wasn’t “clearly established” under existing legal precedents.

The ruling drew an unusual concurring opinion from Judge Don Willett, a widely respected conservative jurist who is on President Donald Trump’s original shortlist for Supreme Court nominees. Willett labeled his concurrence as “dubitante,” a Latin legal phrase used by judges to signal misgivings about their own rulings. He argued not that his court had incorrectly applied Supreme Court precedents, but that those precedents are the real problem. “The court is right about Dr. Zadeh’s rights: They were violated,” he wrote. “But owing to a legal deus ex machina—the ‘clearly established law’ prong of qualified-immunity analysis—the violation eludes vindication.”

Willett’s opinion adds to the growing criticism of how the Supreme Court has shaped qualified immunity over the years. This burgeoning pushback includes two of the high court’s justices, and an unlikely pair at that: conservative Clarence Thomas, who has signaled his displeasure on originalist grounds, and liberal Sonia Sotomayor, who has objected to the doctrine’s tendency to protect public officials in cases of clear wrongdoing.

Qualified immunity isn’t in mortal danger yet, but the ranks of powerful opponents to it are growing. If the doctrine is eventually weakened or even eliminated, it would expand citizens’ right to seek remedies against public officials, including police officers, who have wronged them—and could prevent future constitutional wrongs.