That joke, and its variants is very offensive to many of the the people that live on Guam.
It shouldn't be. The joke is on Democrat Congressman Hank Johnson, who doesn't have the Intelligence Quotient to be a bus driver, much less a Congressman.
https://www.youtube.com/watch?v=v7XXVLKWd3Q
Interestingly, the Navy Admiral who had to endure that ignoramus while trying to keep a straight face was a young Naval aviator during the filming of the movie, and he flew in most of the actual action sequences you see in the film.