Eugene Volokh attempts a (limited) defense for Professor Brandon, the self-parodying Duke professor.
The problem with his attempt is that, in defending the 'implicit' assumption in Brandon's statements, he has to make an explicit assumption that is wildly incorrect on it's face - that a full SIXTY PERCENT (!) of Americans are "stupid"! That would necessitate calling a decent number of people of ABOVE AVERAGE intelligence "stupid", plus also disparaging people of average or only slightly below average intelligence. Absurd.
Let's use Professor Volokh's numbers using a more reasonable percentage. To make things as simple as possible, let's halve his figure, and instead use 30% (though I'd say that even that is too high) while keeping all his other estimates. This gives us, per his stated formula:
(400-(.3*.6)/(1000-300))=220/700= 31%
This would give us three times as many "smart" conservatives.