John Edwards has predicted he can win in the South in 2008. "I think I have the strongest chance of changing the electoral map," Mr. Edwards told the Associated Press earlier this month. "I think we have a great chance to win, not just Ohio, but to win some Southern states." Mr. Edwards is right and wrong. A South Carolina native who was educated and now lives in North Carolina, Mr. Edwards has a built-in edge over his fellow Democrats, none of whom is from the South. Yet, even if he finds a way to translate that backyard advantage into...