In an interview a day earlier, David Ralston, a Republican who is the Georgia House speaker, said, “Georgians are going to have the clearest choice that they’ve probably ever had in a general election for the office of governor.”

To those in between, the chasm between Mr. Kemp, who has adopted President Trump’s language on guns and immigration, and Ms. Abrams, who supports an assault rifle ban and says her “soul rests with those seeking asylum,” feels as vast as Tallulah Gorge.

“It would be nice if we had a more moderate option,” said Kathrine DeLash, who works at a pet store in suburban Cobb County and doesn’t identify with either political party. “You don’t get that with the candidates we have right now. The people who shout the most to their own people get the most attention, and it doesn’t matter what they’re saying as long as they shout the loudest.”

Lynn Westmoreland, a former Republican congressman from western Georgia, said he could not remember another Georgia campaign where candidates did not reflexively move to the center after securing their nominations. “I think the Republicans are losing the middle, I think the Democrats are losing the middle, and the middle is kind of shrugging like, ‘O.K., what am I supposed to be doing?’” he said.

Former Gov. Roy E. Barnes, the last Democrat to hold the office, mourned what he depicted as the disenfranchisement of the state’s political center.

“In Georgia, we always enjoyed a broad middle and we had a broad consensus,” said Mr. Barnes, who served one term but lost his re-election in 2002 and a comeback bid eight years later. “We were all very much in favor of public education. We kept really controversial issues down by an unwritten agreement. But the middle has gone, and it has gone to the extremes unfortunately. It is a microcosm of what is happening in the country.”