In December, another judge in the Central District of California denied an injunction in a similar case. The split verdicts raise the likelihood that the law’s fate could ultimately be decided at the U.S. Court of Appeals for the Ninth Circuit in San Francisco.

“I think the judge saw the law for what it was: an attempt to silence doctors who disagree” with recommendations of the Centers for Disease Control and Prevention or other regulatory bodies, said Jenin Younes, a lawyer with the New Civil Liberties Alliance in Washington who represented five doctors who brought the lawsuit.

Judge Shubb, who was appointed by President George H.W. Bush in 1990, wrote in his ruling that he did not consider the question of whether the law violates First Amendment protections of free speech. Instead, he found that the law’s provisions violated the plaintiffs’ rights of due process under the 14th Amendment.

The law expanded the authority of the Medical Board of California, which licenses doctors, to designate spreading false or misleading medical information to patients as “unprofessional conduct.” That could lead to a suspension or revocation of a doctor’s license to practice in the state.

Judge Shubb ruled that the definition of misinformation — “false information that is contradicted by contemporary scientific consensus contrary to the standard of care” — could have a chilling effect on doctors’ interactions with their patients. He granted a preliminary injunction to block the law, pending a full hearing of the complaint.