If no candidate receives 50 percent support in the crowded primary field, there will be a runoff.
“Part of this is the collapse of the G.O.P.’s Southern strategy,” Mr. Ossoff said in an interview, referring to the controversial political playbook, attributed to former President Richard M. Nixon, that Republicans used to win over white voters in the South.
“We were meant to be distracted by racial and cultural division, but Georgia has moved beyond that,” he said. “And the coalition that’s already being built statewide right now transcends race, transcends urban and suburban and rural divides, and transcends regionalism. And we’re seeing that play out across the South.”
DuBose Porter, a former State House Democratic leader and party chairman who ran for governor in 2010, said that if Mr. Biden wanted to emphasize Georgia’s importance — both to the Electoral College and the Senate — he would select Ms. Abrams as his running mate.
“I think we’ll get there already,” Mr. Porter said. “But if Joe Biden were to select Stacey Abrams, I think that could put us over the top and create some excitement in such an important cycle.”
He did not mention Mayor Keisha Lance Bottoms of Atlanta, who is also seen as a possible choice for Mr. Biden’s number two.
All told, Georgia Democrats see 2020 as a culmination of years of planning, arguing that their previous electoral shortcomings were not failures but building blocks. Their confidence comes as Democrats across the country believe they are well positioned to make Mr. Trump a one-term president, and public polling shows Mr. Biden with a lead that has only improved in recent weeks.
Mr. Trump’s reaction to both the coronavirus pandemic and the national protests over police brutality has drawn criticism from even some members of his own party. And in Georgia, where growing metropolitan areas have led to an influx of new residents and suburban voters have flocked to Democrats in increasing numbers, the president’s actions could hold particular weight.