Fulton County, anchored by Atlanta, as well as surrounding Cobb, DeKalb, Gwinnett, Clayton, Henry, and Forsyth counties, provided the nexus of Democratic strength in the runoffs. In Fulton County, Democrats romped during this election cycle — Biden beat Trump countywide 73% to 26%, banking a nearly 243,000-vote margin on his way to winning the state by about 12,000 votes. DeKalb and Clayton, with their large middle-class Black populations, have become growing Democratic bulwarks in statewide elections and gave both Ossoff and Warnock well over 80% of the vote in the runoffs. However, Cobb, Gwinnett, and Henry counties, longtime Republican strongholds,...