Hey I'm white and I'm sure as shit glad I'm not a "cracker..."
not trying to get in your face, but I think it's best to try and contextualize where each individual might be coming from, especially in light of the topics discussed here....
I think the "cracker" reference is more a persona-reference than anything else... it's just that some people really fill-out these roles.... (I mean damn, watch MTV for a minute) and while ideally we shouldn't use them, people can't help but write and speak contextually, so they are used....