Barack Obama won the state of Mississipi last night as expected, though by a big margin: 61% to 37%. As many news organisations including the New York Times point out: “The polls found that roughly 90 percent of black voters supported Mr. Obama, but only a third of white voters did.”

The implication may be that Obama can’t win white votes. But clearly that’s not true since he won states like Iowa, Kansas and Vermont that have a negligible black population. It seems more the case that in racially diverse states Obama splits the vote, whereas in largely homogenous states white voters have no problem supporting him. Why might this be the case?

Is it like white flight in a residential area where one or two black/brown neighbours are ok, but as soon as the percentage gets high enough, white people start moving out in droves? Or is it the case that in racially mixed states, whites know that blacks will support him so they take HRC’s side? Or is it that in racially diverse states, whites have a less benign view of blacks generally and that affects their voting behaviour? Not much research seems to have been done into this.