Proponents of restrictions on how U.S. public schools address sexual orientation and gender identity say their ultimate goal is to allow parents more involvement in their children's education and ensure classroom materials are age-appropriate.

But in heated debates at school board meetings and in statehouses across the country, the argument they repeatedly put forth is that they are trying to prevent children from being "groomed" — the same term commonly used to describe how sex offenders initiate contact with their victims.

The use of such rhetoric, opponents of the new laws argue, underscore...