It is about race. Specifically, the proposed cities of East Cobb and Vinings have carved out the census tracts with the lowest Black population in the county when drawing their boundaries.
The only census tract with a Black population of lower than 5 percent Black that East Cobb or Vinings did not divvy up was tract 303.43, just north of Shallowford Road bordering Fulton County.
For comparison, the percentage of Cobb’s population identifying as “Black alone” in the latest census is 28.8 percent.
To demonstrate the point, here’s a screenshot from the 2020 Census Demographic Data Map Viewer with the Black or African American tab selected. Arrows were added to label the locations of the proposed cities of East Cobb, Lost Mountain and Vinings.
You can access the interactive versions of this map by visiting this link, then clicking on the “Race Alone” tab, the “Black or African American” tab, then clicking on the little magnifying glass search icon and entering Cobb County, GA, USA.
The lighter areas on the map represent the census tracts with the lowest Black population in the county. The East Cobb and Vinings maps are dominated by tracts with fewer than 5 percent Black population.
To put this in the starkest relief, look at this detail from 2020 Census Demographic Data Map Viewer of the boundary on the western edge of the proposed City of East Cobb, along Old Canton and Murdock Roads.
The East Cobb city limits roughly follow the border between areas with a Black population of below 5 percent (inside the proposed city limits) and outside the boundaries (5 to 10 percent Black population).
The highest Black population in any census tract in the proposed city of East Cobb is a sliver of census tract 303.54 along the river. The whole census tract has a Black population of 7.3 percent, although the riverfront area is the only part of the tract claimed by the proposed city.
The aspiring city also picked up a section on the very northernmost tip of their map, below where Davis Road and Shallowford Road intersect, a portion of census tract 303.27, with a seven percent Black population.
Vinings is easier to visualize. They kept the city limits relatively small, dominated by census tract 312.12 with a Black population of 2.7 percent, and expanded just enough to take in adjacent commercial and industrial areas.
The proposed City of Mableton has the highest percentage of census tracts with a significant percentage of Black residents, with the tracts along I-20 all higher than 75 percent of the population identifying as “Black or African American alone.”
Lost Mountain has census tracts that are more comparable to countywide averages but the census tracts forming the core of the proposed city have a less than 10 percent Black population.