True story-- I have a slang dictionary printed in the 60's that details the origins, meaning and use of slang words from the 1800's on up, and apparently cracker (or cracka) is derogatory black useage for a leftist white person, whereas honky refers to a white rightwinger.
I think the distinction (and thus the terms' rich tradition/heritage) has been blurred these days by careless misuse. Perhaps proud grammarians should fight to take it back
cracker - someone who cracks the whip
aka slave master