(If you overlay the precinct-level results from https://s3.us-west-2.amazonaws.com/cobbcounty.org.if-us-west... on a demographic map, it becomes apparent that the more educated parts of Cobb are redder than the less educated parts. This correlates basically perfectly with the less white vs. whiter parts).

I'm from Smyrna originally and lived there for the majority of my life. East Cobb (although it is purpleish, not just red, and that is due to college education) is redder than Smyrna/Marietta, despite being much more educated.