Unlikely, since non-white voters were probably above 25% of the GA electorate, and would be breaking extremely lopsided to Carter (more than a 60 point margin for sure). GA was within 15% in 1980.
I have to reject this claim. GA SoS records race by voter registration and turnout: non-whites didn't reach 25% of the electorate in GA until 2004. Unless a ton of non-whites were identifying as white when they registered (which back then would've been very unlikely), there's no argument for them being anywhere close to 25% in 1980.
Even before this particular metric, I was also skeptical that Carter didn't win a majority of whites in the less racially progressive states of SC & AL in 1976. After all, these county maps (AL, SC) basically mean that unless a large segment of white voters resided in this handful of "ancestrally-GOP" counties in 1976, that the overwhelmingly rural white counties that all went for Carter indicate a trend.
Mobile & Jefferson Counties were a higher portion of state population than today, Madison less. So I think it is consistent with a narrow Ford win of the white vote, esp. given you can imagine many more counties R without the black vote. Still the map is also consistent with a narrow Carter win of the white vote, where his strength in the north of the state makes up for a small deficit elsewhere. Similar dynamic with strong white support for Ford in Greenville and Charleston. If black proportion of vote is 15% in AL and 20% in SC, going 85% for Carter, then in both states the white vote would be split evenly.
