Here's a cool map of metro Atlanta in 2008
As you can see, there's a core base of democratic support in the city of Atlanta and the inner southern suburbs. This is where there's a ton of black voters and hipster liberals. Then it gets interesting as that blue sort of fans out in all directions from the city along the interstates- this is also where a lot of minority voters live. Then, as you get farther out into the outer suburbs it becomes almost blood red. These areas are white and conservative, and people there only go into the city for Braves games and concerts. And god forbid MARTA tries to expand into their communities.
In terms of areas outside ATL that are white and liberal, you'll really only find that in areas of Dekalb county like Decatur and a few scattered areas of North Fulton where a lot of wealthy northeastern transplants have put down roots.
For the most part, there aren't really any swingy regions in the metro area. The Democratic regions are super, super democrat, and the Republican regions are almost maniacally loyal to the GOP.
as is tradition (in the South).