The latest National Review contains this article (subscription required) about the spanking debate (whether or not to spank one's children). It's an odd piece that skips not lightly from presenting the controversy's history, to illustrating the problems with a spanking ban, to hypothesizing that less spanking has spawned the prevalence of pharmaceutical methods of youth discipline, to weirdly comparing the "choice" to spank to the "choice" to have an abortion.
Nonetheless, out of the convolutions can be plucked several useful bits. First, that the evidence for and against spanking is inconclusive, and second, that the practice works for some parents and doesn't work for others.
It seems safe to apply these to the k-12 setting and also make an argument for educational choice, which is that parents ought to have the choice to enroll their children in a school that exercises reasonable forms of physical discipline if parents so choose. To say that the watered down discipline at most public schools results from the fact that such schools enroll students whose parents subscribe to radically different notions of appropriate punishment is not to be wrong.