This is the Dunning-Kruger Effect.
The Dunning-Kruger effect occurs when incompetent people not only fail to recognize their own incompetence, but actually consider themselves much more competent than everyone else.
Basically - they're too stupid to know that they're stupid. .
Charles Darwin once noted, “Ignorance more frequently begets confidence than does knowledge.”
I think that explains the narcisstic arrogance of democrats like Nancy Pelosi, Harry Reid, Barney Frank and Barack and Michelle Obama very well.
The people who wrote the article you linked are excellent examples of the phenomenon they document.
That's an oldie but goodie. I was stuned not too many years ago to discover the more I learned the less I knew.
The path to arrogance is unencumbered when you don't fathom how shallow is the knowledge you command. In reference to modern politics I call it the Obama-Biden effect.