so what? not everyone uses the terms to mean the same thing. I have lived around Black people my entire life, and many of them use the word “ass” frequently, with no grammatical sense to the word much of the time.
“Cracker” is the dominant word here, it is like “white as a cracker” or “Whip cracker” from slave days. It is a derogatory word for White people.
It's not a very effective one.