God exhorts parents to discipline their children including spanking, when necessary, but it cannot be done out of anger.
I find that most people who are very averse to corporal punishment were abused by their parents (spanked out of frustration or anger), but past misuse of the tool does not negate the command.
Proverbs 13:24, 23:13-14, 22:15, 29:17, 19:18
The best pro-spanking people can say is that it doesn't really do anything (so let me use the laziest possible "parenting" technique instead of actually parenting my kid)