COLUMBUS, Ohio (AP) — Witches were still being burned at the stake when Sir Matthew Hale came up with his legal theory that rape could not happen within marriage. The 17th century English jurist declared it legally impossible because wedding vows implied a wife's ongoing consent to sex.

Three and a half centuries later, vestiges of the so-called "marital rape exemption" or "spousal defense" still exist in most states — remnants of the English common law that helped inform American legal traditions. Legislative attempts to end or modify those exemptions have a mixed record but have received ren...