The official purpose of Joseph R. Biden Jr.’s trip to Georgia in the final days of 2020 was to rally support for two Democratic Senate candidates facing tight runoffs. But the visit looked an awful lot like a victory lap.

“I have to say, it feels pretty good,” Mr. Biden told a crowd in Atlanta, reveling in the distinction of being the first Democrat to win Georgia in a presidential election in nearly 30 years. The moment — along with the Democrats’ win of both Senate seats a few weeks later, tipping control of the chamber — seemed to affirm the party’s resurgence in a state long dominated by Republicans.

This weekend, as Mr. Biden returns to Atlanta with ambitions of winning the state again in a rematch with former President Donald J. Trump, he faces a much different climate.

The optimism that soared among Georgia Democrats after his win has been overtaken by frustration and worry, not just about his campaign prospects but also about the direction of the country.