In Oxford, Mississippi

In Ajax bar in Oxford, Mississippi, they muted the baseball commentary during the Obama-Romney debate and left the game playing on the screen near the door while the candidates sparred on the big screen over the bar. We couldn't make out the nitty-gritty of what they were saying, just the mood music: Mitt v. Barack sounded like marching band Sousa v. the Well-Tempered Clavier.

Oxford has two black presidents these days. Besides Obama there's Kimbrely Dandridge, an African-American woman elected in February to head the student body of the university of Mississippi, which has its main campus here. The timing had resonance. A few days ago was the 50th anniversary of the enrolment of the previously all-white university's first black student, James Meredith. When a mob of enraged segregationists tried to block Meredith, President Kennedy ordered in federal troops – the biggest deployment of federal troops on US soil since the Civil War – and in the battle that followed, two people were killed. Meredith and Kennedy prevailed and formal segregation was ended, only for a long struggle to begin by black students to be accepted as the intellectual and social equals of their white peers.

Outside the bar on the night of the debate, in the soft humidity of a southern evening in fall, a group of well-to-do young female students chatted by their cars, drinking sodas and exchanging hugs and jokes. The University of Mississippi, Ole Miss, has a reputation as a fun place of parties and football for the children of the wealthy. Three of the students were white; two were black. They hung out there together in quiet unafraid peace on the old town square where a monument to the Confederate dead of the Civil War still stands prominent under the magnolia trees, with its inscription, 'They gave their lives in a just and holy cause' – the cause, to be clear, of freedom for people of one skin colour to enslave people of another.

The leader of the campaign to build the monument in the 1900s was William Faulkner's mother. There may still be places in Oxford where people's race makes them feel unwelcome, but the town's public schools are racially mixed and integrated to a degree unimaginable in Faulkner's time. This is not the case west of Oxford, in the communities of the Delta, between the Yazoo and Mississippi rivers, where the segregation of officially sanctioned racism has been replaced by the segregation of personal choice and economic power. White small farmers have been driven off the land by the rise of corporate farms; the remaining white families, who tend to be better off, send their children to private schools, and the division of the communities is perpetuated by the self-separation of one from the other.

The political trajectory of Obama's presidency began at least partly as the celebration of a singular American triumph against racism. Four years later, Mitt Romney's incredible division of America into the 47 per cent of the damned and the 53 per cent of the saved not on racial or religious but financial grounds confirms that racism is, and always was, a subset of the mixture of contempt, fear and shame any established prosperous class feels towards its poor counterpart. What a hard road of overcoming prejudice to get to this point, only to reach the start of an even harder one: where Romney and Obama face each other not as white Mormon to black Protestant but as neo-aristocrat to salaried professional.