"Poor Joshua " lamented Justice Harry Blackmun in his famous dissent. "Victim of repeated attacks by an irresponsible, bullying, obviously cowardly, and intemperate father, and abandoned by respondents who placed him in a dangerous predicament and who knew or learned what was going on, and yet did essentially nothing. . . ." Even so, the Supreme Court, by a 6-to-3 margin, absolved Wisconsin officials of any negligence in a case that had left a young child profoundly damaged for the rest of his life.

Does the Constitution protect children from violent parents? As Lynne Curry shows, that...