Still, Ms. Abrams acknowledged that “electoral politics tends to lag behind demographic changes.”
The demographics, though, account for much of the reason that the state has grown more politically competitive.
There has been a population explosion around Atlanta, thanks to an influx of Asian, African and Hispanic immigrants as well as a migration of native-born Americans, white and Black alike, who have moved to the region because of family ties, the relatively affordable cost of living and expansive job opportunities.
Although long identified with Coca-Cola and Delta Air Lines, the city has become a corporate behemoth, home to companies like UPS and Home Depot as well as to the American headquarters of the carmakers Mercedes and Porsche.
Atlanta itself has long been a mecca for African-Americans but the entire metropolitan region is now diverse, and counties that were once heavily white and solidly Republican are now multiracial bulwarks of Democratic strength.
In 2000, for example, Al Gore received only 31 percent of the vote in Henry County, an exurban Atlanta community that was once dominated by farmland, including that of the former segregationist Senator Herman Talmadge. In November, Mr. Biden won almost 60 percent of the vote in the county, and the jurisdiction elected a Black sheriff for the first time.
Ms. Jordan, the state senator who represents a suburban Atlanta seat, said the population changes would have made Georgia more closely contested this decade but “Trump put a turbo booster on it” in large part because he energized such strong opposition among women.
Sheron Smith, 59, who attended Mr. Ossoff’s drive-in rally in Macon, said her own activism illustrated how the state had changed. Ms. Smith said she was always politically liberal, but did not get involved in organizing until 2016, when Mr. Trump’s election prompted her to join a progressive women’s group in town.