Peale being deep was a reference to an old Tom Lehrer song, "It Makes a Fellow Proud to Be a Soldier"--

"Now Fred's an intellectual, brings a book to every meal.
He likes the deep philosophers, like Norman Vincent Peale."

Ironic, of course. Beside his extreme conservative political views, Peale was noted for his simplistic "Power of Positive Thinking" views, which some have pointed out, seemed often antithetical to basic Christian moral ideas, and, if they didn't outright deny the existence of evil in the world, seemed unconcerned with it.