Pejorative term originally referring to only poor southern whites who "barely survived on eating crackers." Rich whites would call the poor whites "crackers."
Since, it has lost its original meaning the ruling whites intended for these serf-whites and now it is more commonly used by black people to offensively refer to any white person, regardless of social or economic standing.
Looks like those poor white people in the swamps and jungles of LA and MS won't EVER be able to "take the word back" so to speak.
Wealthy Southern Politician: We'll send in a wedge candidate to some of those dumb hick towns and split up the cracker- votes.
Southern Police Chief: We can let a small drug shipment get through and let the niggers and crackers kill each other for it.
Swamp Person: now we'll nevah be able tu "take back" du Cracka name.