I subsequently found this critique (via USS Clueless) which, while I had reservations on several points, seemed well reasoned and rather devastating to Mr Zinmeister's puported data, and by extention to his arguments. Zinmeister's response to the criticisms was, to be charitable, disappointing.
There are few things more irritating than to see someone arguing - poorly! - in favor of position you hold. When you combine that with intellectual dishonesty, it compounds the problem. Therefore, in a follow up post, I will attempt to formulate a more credible reply.