If you captured over 90% of a demographic group (as Democrats do with blacks), wouldn't you try to increase their turnout? If you have 27% of the electorate in the bag, it means you need just over 1/3rd of the remaining electorate to have 51% overall.
Adult population of Georgia is 30% AA and Hispanic 8%. Non Hispanic whites are 52% meaning white females are 26%. A black democrat starts with at least 32% in the bag. Get 50% of the white female vote and you have 45%. Get 20% of the white male vote and you have the election. Get a much higher turnout in the minority vote than normal (ground game is expensive) and you win by a very comfortable margin. Minority turnout and the white female vote are critical.