Part of the argument that Barack Obama can "expand the battlefield" in November is the idea that he can stimulate a major increase in the African-American vote, especially in the South.

Republican Rep. Adam Putnam of Florida has gone public with the fear that an Obama-generated black voter tide could "destroy" down-ballot GOP candidates in the South.

Oddly enough, it's Democrats who have rained on this particular parade. Salon contributor (and my friend) Tom Schaller has sought to pour cold water on the theory by arguing that the Southern black vote is already high, and can't go much higher without producing a pro-GOP white voter tide.

But Tom doesn't (and can't, because there's no direct precedent) deal with the possibility that an African-American presidential candidate could produce a historic black vote that could dwarf any white backlash.

In my home state of Georgia, in 1998, the African-American vote more than doubled over the previous midterm turnout in 1994, considerably exceeding the white voter increase. That happened in part because Georgia Republicans, advised by Ralph Reed, ran a racially oriented campaign. But it also didn't hurt that two African-American Democrats were on the statewide ballot that year.

It's entirely possible that the 1998 pattern could be replicated in the Deep South, particularly if the white conservative disgruntlement with McCain and the Republican Party continues.

This is probably why the Obama campaign is identifying Georgia, as well as North Carolina, as counterintuitive battleground states, and why some Southern Republicans are panicking.