H. L. Mencken? Louis B. Mayer? Arthur L. Mayer? David Ogilvy? P. T. Barnum? Apocryphal? Dear Quote Investigator: A sardonic comment about the general public has been credited to the famous journalist curmudgeon H. L. Mencken. Here are two versions: (1) No one ever went broke underestimating the intelligence of the American public. (2) Nobody …