Skill and Chance pretty much already summarized it. White voters in Georgia are not going to become any more Republican than they already are - at least, not outside of current exit polling margins of error - whereas non-whites continue to become a much larger share of the population and of the voting bloc. When you factor in that Georgia hasn't had any comprehensive voter mobilization campaign by a presidential candidate since 1996
and you look at how Georgia is 47th in percentage of registered voters and 31st in voter turnout, then you can see that there is a lot of potential in improving Democratic performance in the next decade.
Now for my obligatory voter turnout chart:
As weird as it may (or may not) sound, Georgia exit polling showed a very small difference between the youngest and oldest groups and their support for Obama in 2008. However,
for other Democrats, that gap widens quite a bit. In the non-Obama examples, those under the age of 45 are reliably-Democratic, while those over the age of 65 are even more reliably Republican. Some quick and dirty math I did suggests that even
whites under the age of 45 in Georgia are close to 40% Democratic.
The next ten years will see a cohort of whites that are >80% Republican be replaced by a cohort of whites that are only 60% Republican; a cohort of voters that are 60% Republican be replaced by a cohort of voters that are 55% Democratic.
That may seem when calculated to be whittling around the margins, but consider this: Georgia whites were 23% Democratic in 2004 and 2008, and 20% in 2012 (I don't think 20% is the new norm, considering Carter/Nunn both got 23% in 2014). In 2016, 28% of whites voting Democratic flips the state; in 2020, 27%; in 2024, 26%; and so forth. Factoring in what we mentioned above + new movement to the state in the coming years, and you realize that it really ain't gonna take a lot to get us there.