@JTT,
Do you really think that William Safire and William F. Buckley did not have superb vocabularies? If so, please name anyone from the left wing whose vocabulary is superior> I don't know of any and may have missed them!
As far as the meaning of words go, I can take almost any Vocabulary Test and I rarely get a score below 95. I am not a trained linguist but I have studied Latin, Spanish and Polish. I can read French with understanding.
Niggardly is not used frequently but it is not an esoteric word. If Rockhead wrote in such a way as to use a special word once in a while, I would not have characterized him.