My math is a little rusty, but I wanted to offer a little statistical observation relating to ID and being dumb.

Let...
ID = believe in ID
dumb = are dumb

Prior for being dumb: talented tenth (or if you have a certain someone in mind, fill in your own prior)
P(dumb) = 0.9
P(~dumb) = 0.1

Likelihood of believing in ID given you are dumb (or not dumb): I made these values up, but we could probably find survey data to refine those estimates. Try your own guess.
P(ID|dumb) = 0.8
P(ID|~dumb) = 0.4

Bayes rule...
P(dumb|ID) = 0.947
P(dumb|~ID) = 0.750 [correction]