"White privilege"

Why do so many people believe white people cannot experience racism? I read someone's comment on another post about racism saying they were declined from a job multiple times because they needed someone diverse. If you call a white person a "slave owner" or "cracker" that is not racist? Those against racism are against it because it's dehumanizing and they prefer equality. If you tell a white person they can't experience racism because they have a higher social status don't you think that is dehumanizing? So we are for equality as long as white people are excluded? I understand that horrible things happened back in history and still continue to happen which is absolutely unacceptable....however how are we going to change anything  in the future if we don't move forward? Don't use the N word or any other slur for any race if you're white but everyone else can call you "cracker" and whatever else they choose to...........that makes sense. I don't think it's okay to call any race a derogatory name at all. If you can't be racist against a white person then "white" must not be a race.