A federal judge in Iowa temporarily blocked on Friday the enforcement of a law backed by Republicans that banned books describing sex acts from public school libraries.

In granting the preliminary injunction, Judge Stephen Locher said that the law “makes no attempt to target such books in any reasonable way.”

“Instead, it requires the wholesale removal of every book containing a description or visual depiction of a ‘sex act,’ regardless of context,” the judge wrote. “The underlying message is that there is no redeeming value to any such book even if it is a work of history, self-help guide, award-winning novel or other piece of serious literature. In effect, the Legislature has imposed a puritanical ‘pall of orthodoxy’ over school libraries.”

The publisher Penguin Random House and the best-selling authors John Green and Jodi Picoult were among the plaintiffs who challenged the measure on free-speech grounds.