I don't buy the "fomenting of hate by the powers that be" argument. I agree with Azizi's statement when she said "I believe that poor White people in the Southern USA and elsewhere-as a group-if not as individuals-may look down on Black Americans-as a group if not as individuals-because some people have to feel that there's someone worse off than they are. In that sense, some poor White people and other White people do consider their racial identity to be important."
The issue in the South goes back a long way. Before the Civil War, there was no class of free blacks that did farming, labor, and industry. The grunt work and subsistence farming was done by poor whites. I believe the whites valued the meager but significant difference they enjoyed as free, if miserably poor, humans. I also believe that these poor whites evolved a culture that was as markedly different from that of the black slaves as it was from that of the monied whites. These poor whites were the cannon fodder of the Civil War, but it is a mistake to say they died for slavery or such abstractions as states rights. I believe they went to war for the simple belief that they were protecting their homes from invasion, and to keep from losing the small possessions that were theirs. When the war ended, those poor whites who survived returned to devastation, and a new competing group of subsistence workers...freed blacks. You don't need a degree in psychology to imagine the resentment that was felt.
Reconstruction, with its dose of carpetbaggers and the corrupt state and local governments that were setup, the corresponding terrorist response of groups like the Klan, the apartheid that took control as the monied whites regained control, all of this set the stage for hate and prejudice that held sway until the Civil Rights movements of the 1960s, a movement that farsighted leaders like King and Kennedy led that seemed to suggest the possibility of a new way of living together. With the integration of schools, even sports opened up to encounters between blacks and whites. On a national level, we probably now enjoy an amount of healthy interaction at least comparable between that of Australians and Aboriginal people, or between New Zealanders and Maoris.
Are their areas where ignorance and hate still hold sway? No doubt about it. But poor white trash in Mississippi are probably no more to be disdained than poor Irish in Boston, or poor Irish in Derry for that matter. However,I suppose its often easier to focus on the perceived ignorance and racism of those safely ensconced somewhere in the Old South, than it is to look closer to home and come uncomfortably close to being confronted by our own weaknesses and foibles.