As we all understand, Republicans are about to have a pretty good election in November. Much of the GOP excitement revolves around congressional races that could unseat “red-state” Democrats who won during the 2006 or 2008 cycles, along with a number of incumbents (some of whom have decided to retire) who have been around much longer. Ground zero for the Republican tsunami is, of course, the Deep South, where in some areas John McCain did better in 2008 than George W. Bush did in 2004, and where every available indicator shows the president to be very unpopular among white voters. 

But beneath this storyline, some odd and counterintuitive things are going on. In three Deep South states, Georgia, Alabama, and South Carolina, Democrats have a decent chance of retaking...