The bedrock reality of censorship is that it doesn’t work. Things learned cannot be unlearned. Confused, distorted, condemned,    even forgotten, but never erased. So battles over access to knowledge ultimately are nothing but struggles for power. Check out the early part of Geneses in the Bible. Or catch Sheri Wilner’s new play Kingdom City, now at the La Jolla Playhouse. It’s a raggedy play in a problematic production but it does address the issue: A creative couple from Manhattan are dropped into a rural Missouri town where he’s a visiting scholar at the local college and she’s hired to direct…