Can't say I'm surprised; the US has a long history of attacking the character of people who rustle the feathers of the establishment (most notably martin luther king).
Have you read Killing Kennedy? It wasn't great and I wouldn't bother, but it did have an interesting part about Kennedy meeting with MLK early in the civil rights battle and warning him to be more discrete about his extramarital transgressions. Hoover hated MLK, thought he was a Communist, thought nearly everyone involved with the civil rights movement was a Communist (probably a gross oversimplification on Bill O'Reilly's part) -- so Kennedy essentially told MLK, we're watching you, be careful, if we're going to get in bed with you politically you need to stop getting in bed with young women literally. Ironic of course coming from Kennedy.