Show how ridiculous these bans are. I don't smoke, and don't like it that much when I'm around it. But it's a legal activity, and the owner of the establishment should have the right to determine whether or not smoking is allowed. The market will determine which is the proper course of action.
I'd be in favor of that. At least, ill-behaved children of liberal yuppie parents who consider any form of discipline as child-abuse.