In the USA “racial humor” is a trap. The officially-designated victim can make fun of the “oppressor” class, and in fact may even go so far as to murder a member of the “oppressor” class without any consequences.
But if a member of the “oppressor” class says “watermelon” he loses his job and his reputation.
And if there is ANY HINT that the “oppressor” class doesn’t really oppress or that the “victim” class isn’t really being victimized,
they raise HELL to get the hinter silenced.
There’s power in maintaining the illusion of the “oppressor/victim” context.