With the national exit poll showing Obama winning with just 39 percent of white voters, a smaller share than any Democrat since Mondale, the emerging conventional wisdom holds that a demographic tidal wave of minority turnout cost Romney the presidency. As a result, Republicans are focusing on their poor performance with the burgeoning Latino population; even Sean Hannity says he's "evolved" on immigration reform. But while the national exit poll data give the impression that Romney got the job done with white voters, Romney's stellar national performance obscures stark regional differences that suggest the GOP has its own problem with white voters.
Romney’s strong national showing among white voters was almost exclusively driven by historic support from Southern and Appalachian white voters. In many counties, Obama’s performance was the worst by any Democrat since McGovern or, in some places, ever. Even a quick glance at overwhelmingly white, Southern, or Appalachian counties with a history of offering even limited support to Democratic candidates shows Obama performing anywhere from 15 to 30 points worse than Kerry did eight years ago. Obama even lost more than 50 points compared to Kerry’s performance in several “coal country” counties in southern West Virginia and eastern Kentucky.
Lots more at article
A summary is that Obama got his historic low white vote percentage by doing the worst ever in Appalachia and the South but doing better than either Kerry or Gore in the Midwest and East. But since you can only lose states such as Kentucky, Arkansas, Oklahoma, and West Virginia once those Appalachian and Southern voters didn't do Romney much good.