I wasn't being sarcastic; were you? White people - the majority, the powerful, the "rulers" of America - will never face the racism that black people do. Even if you face racism as an individual in high school, that racism is contained in a local environment and does not represent the history of the country you do.
That's why the word "nigger" will always be more powerful than the word "cracker". Call me a cracker, sure. I don't care; that word is powerless. Nigger, though? That's a strong word not because what it means right now, but what baggage it carries along with it. It's really easy for white people to dismiss racism or claim that they have faced racism; it's not the same. At all.