You jest but half a country are below average intelligence. It’s not outlandish to think that many individuals in that half aren’t really following what is being said or understand it. What they can follow is the visuals. How they look, how they stand, how they move; how they “read”. And a non-trivial number of above average people still judge books by their covers.

I think the point the person above was trying to make is that Vance won the area the majority of people can evaluate and the importance of visuals.