These results got a lot of attention from people as far apart as Dave Neiwert and Kathleen Parker. And David Weigel pointed out that nonwhites in the South, who make up over thirty percent of the population there, were just as sure that Obama was born is America as people from the other regions. It's the white people in the South who don't believe Obama was born in America; Weigel estimates that the number of whites answering "no" or "unsure" had to be around seventy-five percent to produce these polling results.
The logical question to ask at this point: why are Southern whites so different from everyone else in the country? The answer goes back, I think, to the Supreme Court's 1954 Brown v. Board of Education decision and the resulting desegregation of Southern public schools. As soon as a public school system in the South was desegregated, white parents would pull their children out of the public schools and send them to whites-only private schools that were nicknamed segregation academies. These children, the Resegregated, would grow up, get married, have children of their own, and send them to the same whites-only private schools they had attended. In this way, a whites-only subculture was born in the South centered around a reactionary private school system (and also, incidentally, a reactionary fundamentalist version of Christianity). This Resegregated culture has remained stuck in the Jim Crow era while the rest of the country has moved on to the point of electing a black president.
The Resegregated whites of the South have become a backwater, drifting further and further away from the mainstream American culture. Thanks to Richard Nixon's Southern Strategy, the Resegregated have become a core constituency of the Republican Party, which is the main reason the GOP has begun shrinking into a regional party based in the South. As the Resegregated become less like other Americans, they will continue to drag the Republican Party after them, until either the GOP manages to free itself from their grasp, or it goes the way of the Federalists.