Joe Biden put Georgia in the Democratic column for the first time since 1992 by making huge gains among affluent, college-educated and older voters in the suburbs around Atlanta, according to an Upshot analysis of the results by precinct. The Black share of the electorate fell to its lowest level since 2006, based on an Upshot analysis of newly published turnout data from the Georgia secretary of state. In an election marked by a big rise in turnout, Black turnout increased, too, but less than that of some other groups.

The findings suggest that Mr. Biden’s win in Georgia may not yet herald a new progressive majority in what was a reliably red state, as Democrats still depend on the support of traditionally conservative voters to win statewide. It helps explain why Republican candidates won more votes than Democrats in the state’s two Senate contests, even as President Trump was defeated at the top of the ticket.

But the relatively low Black share of the electorate could mean that Democrats have the potential for a better showing, perhaps even in the two Senate runoffs in January.