I think one thing Razib says is exactly right:
One of the most interesting things to me is the nature of Creationism as an idea which evolves in a rather protean fashion in reaction to the broader cultural selection pressures.
Creationism has evolved significantly, but it’s not exactly protean: it’s punctuated equilibrium. If we had a time machine and could bring a typical creationist who came to age after Whitcomb and Morris’s The Genesis Flood face-to-face with a pre-Scopes trial creationist, there would be a fabulously ferocious fight, because their theology and their basic beliefs would be so radically different. They do change in response to the environment, but reluctantly and not without a lot of hysteresis.