Assuming human intelligence naturally follows a normal distribution model plus add in confounding factors like: malnutrition, chemicals, abuse, etc. that are known to degrade human reasoning. Reasoning is further restricted by limiting access to education and extensive false propaganda. These factors flattens and shift the distribution curve to the left.

The millions of people who voted for him are morons what are easily manipulated by their ignorance and fear.

This has always been the Achilles heal of a democratic systems.