… is from pages 120-121 of the 1987 edition of the 1968 collection H.L. Mencken’s Smart Set Criticism  (William H. Nolte, ed.); specifically, it’s from Mencken’s brilliant 1921 essay “The Style of Woodrow” (available on-line here ), Mencken’s review of William Bayard Hale’s book about Woodrow Wilson:
What intrigued such gentlemen [the press corps] in the compositions of Dr. Wilson was the plain fact that he was their superior in their own special field – that he accomplished with a great deal more skill than they did themselves the great task of reducing all the difficulties of the hour to a few sonorous and unintelligible phrases, often with theological overtones – that he knew better than they did how to arrest and enchant the boobery with words that were simply words, and nothing else. The vulgar like and respect that sort of balderdash. A discourse packed with valid ideas, accurately expressed, is quite incomprehensible to them. What they want is the sough of vague and comforting words – words cast into phrases made familiar to them by the whooping of their customary political and ecclesiastical rabble-rousers, and by the highfalutin style of the newspapers that they read. Woodrow knew how to conjure up such words. He knew how to make them glow, and weep. He wasted no time upon the heads of his dupes, but aimed directly at their ears, diaphragms and hearts.
But reading his speeches in cold blood offers a curious experience. It is difficult to believe that even idiots ever succumbed to such transparent contradictions, to such gaudy processions of mere counter-words, to so vast and obvious a nonsensicality. Hale produces sentence after sentence that has no apparent meaning at all – stuff quite as bad as the worst bosh of the Hon. Gamaliel Harding. When Wilson got upon his legs in those days he seems to have gone into a sort of trance, with all the peculiar illusions and delusions that belong to a frenzied pedagogue.