An Oregon father rapes his 12-year-old daughter, whom he has abused before. She protests, but doesn’t fight because she’s afraid he’ll fight back. He’s tried and convicted, but the conviction is reversed on appeal because the girl didn’t fight.

The message that “no means no” has been central to the movement to reduce sexual assault on college campuses.... But this message often doesn’t line up with legal reality. A majority of states still erect a far higher barrier to prosecution and conviction by relying “on the concept of force in defining rape,” as the Northwestern University law professor Deborah Tuerkheimer writes in a forthcoming article in The Emory Law Journal. Tuerkheimer finds that in more than half of the 50 states, a judge or jury must find that a person used force to find him or her guilty of rape. The Model Penal Code, created by the American Law Institute in 1962 to influence and standardize criminal lawmaking, also continues to include a force requirement in its definition of rape.