In 2005 and 2006, two moderate Democratic candidates, Jim Webb and Tim Kaine, won in Virginia with large margins in the Washington suburbs. Their victories demonstrated that there was a new path to victory for Democrats, one that did not depend on winning Southern conservative Democrats, the way Mark Warner did in 2001.

Georgia might well be moving down the same road as Virginia. No other plausibly competitive state — not Nevada or Virginia, not Colorado or North Carolina — has had a change in the racial composition of the electorate that’s as favorable for Democrats. That’s giving Georgia Democrats hope that they might win a race that they almost certainly would have viewed as a lost cause only a few years ago.

The Senate matchup in Georgia was finally set Tuesday night, when David Perdue won the Republican nomination by defeating Jack Kingston in a runoff primary. Mr. Perdue, a businessman, is not a candidate who is expected to implode on the campaign trail, the way some Republicans have over the last few cycles. But he is not especially experienced, and some believe he could be caricatured in some of the same ways Mitt Romney was.

On the other side is Michelle Nunn, a former chief executive of the Points of Light volunteer group and the daughter of Sam Nunn, a renowned former senator from Georgia. The Democratic window to victory remains very narrow, and a Blue Georgia might still be a few years off, but Ms. Nunn is well suited to try to pry it open.