I did some "my numbers" on the impact demographic shifts are having on Georgia's electorate. Trends suggest that the GA electorate in 2016 will be around 57% white, 32% black and 11% "other". From what can be gathered by looking at the election results & turnout by race and comparing them with 2008, it appears as if Obama got 20% of the white vote in 2012 (versus 23% in 2008).
The takeaway is that if Hillary (or any candidate) can raise her share of the white vote in Georgia to a mind-numbing 25%, they win Georgia comfortably (51-48%) in 2016. I'm betting she can.