Nothing is more confounding to the smug style than the fact that the average Republican is better educated and has a higher IQ than the average Democrat. That for every overpowered study finding superior liberal open-mindedness and intellect and knowledge, there is one to suggest that Republicans have the better of these qualities.
Most damning, perhaps, to the fancy liberal self-conception: Republicans score higher in susceptibility to persuasion. They are willing to change their minds more often.
The Republican coalition tends toward the center: educated enough, smart enough, informed enough.
The Democratic coalition in the 21st century is bifurcated: It has the postgraduates, but it has the disenfranchised urban poor as well, a group better defined by race and immigration status than by class. There are more Americans without high school diplomas than in possession of doctoral degrees. The math proceeds from there.