" It is a little-known but significant fact that no president has appeared more times in Superman comic books than JFK. He was even entrusted with Superman's secret identity and once pretended to be Clark Kent so as to prevent it from being exposed. When Supergirl debuted as a character, she was formally presented to the Kennedys. (Not surprisingly, the president took an immediate liking to her.) In a special issue dedicated to getting American youth to become physically fit — just like the astronaut 'Colonel Glenn' — Kennedy enlists Superman on a mission to close 'the muscle gap'. "

― Jonah Goldberg , Liberal Fascism: The Secret History of the American Left from Mussolini to the Politics of Meaning