North Georgia is heavily Republican, with its loyal to party roots going all the way back to the 1800s.
I thought north GA was pretty friendly to Zell Miller type Dems.
I assumed this was more of a national/Presidential discussion on state divides. There are levels to how the regions in Georgia vote depending on whether it's local, state or national.
For example, Chattooga County, Georgia still hasn't had a Republican elected to local office. They continue to support Democrats at the state and national level by larger margins despite being surrounded by staunch Republicanism, but the area will probably never vote for a Democratic president again. It's an isolated, older community. This would be a more accurate display of local/state trends:
Dixiecrats did alright in NE Georgia in the post-Civil Rights era oddly enough but it was mainly at the local and state levels. I believe Ed Jenkins was our last Democratic congressman from North Georgia through 1992. Nathan Deal was a Democrat for his first term before flipping in 1995. Zell Miller did well specifically because he was from Towns County. The Democratic Party is essentially dead throughout the uber-vast majority of North Georgia.
A lot of North Georgia was pro-Union and have stuck with the party by and large since then. Over time, though, the area changed with the party. It's always been conservative but has gotten worse in recent decades. It's harder to observe the trends for Presidential elections in North Georgia throughout the 1960s, 1970s and 1980s but it's still fairly clear; LBJ won in traditional Republican bastions of North Georgia and then Nixon won over Wallace, due to less support for segregationist policies. They obviously went on to support Nixon again, followed by Carter twice (given). It's been reliably Republican for presidents since then.