Joseph R. Biden claimed the White House for Democrats this weekend. Whether he will be able to get much accomplished depends on what happens in two months in Georgia.
Two Senate runoff elections are slated for Jan. 5, and they are expected to determine whether Republicans will keep control of the chamber, and the ability to derail Mr. Biden’s plans, or whether Democrats will take control.
“Now we take Georgia, then we change America,” Senate Minority Leader Charles E. Schumer, New York Democrat, said in the minutes after Mr. Biden declared victory.
Although Mr. Schumer pointedly highlighted what’s at stake, it’s not clear whether his nationalizing of the race helps the Democrats in the state race.
Political analysts said they expect the two Democrats, Jon Ossoff and Raphael Warnock, to try to avoid getting too deep in the politics at the national level, where Mr. Biden, the presumptive president-elect, will be choosing his Cabinet members and plotting his first moves after four years of President Trump’s executive actions.
The two Republican incumbents, Sens. David Perdue and Kelly Loeffler, are likely to make the Democrats sweat each Biden move by demanding to know whether Mr. Ossoff and Mr. Warnock support the incoming president.
“Now, more than ever, we NEED to keep the Senate in Republican hands,” Ms. Loeffler said in a Twitter post after Mr. Biden’s declaration of victory. She said she and Mr. Perdue are “the last line of defense against the radical left.”
The Democrats are likely to counter with the same accusations of corruption they fired at the Republicans in recent months.
“It will probably be the exact same campaigns we saw in the general election, with the same messaging: socialists versus crooks,” said one veteran Georgia political operative.
That framework worked for Mr. Perdue in the general election — just not by enough. He led Mr. Ossoff 49.8% to 47.9% as of Sunday afternoon, putting him just shy of the 50% threshold that would have avoided a runoff.
The other race featured a larger field, including two high-profile Republicans, Ms. Loeffler and Rep. Doug Collins, who battled each other, split the party’s vote and allowed Mr. Warnock to emerge with the most votes at 32.9%. Ms. Loeffler was second with 25.9%, giving her the right to face off against Mr. Warnock.
The two races have quickly fused into one.
Ms. Loefler and Mr. Perdue are portraying themselves as a package deal, and so are the Democrats, who have set up a joint fundraising operation.
Andra Gillespie, a political scientist at Emory University, said she expects the elections to become a battle over who can mobilize base voters better.
“Given the near parity of Democratic and Republican voters in the state and the fact that turnout will decline in January, whichever party has the best GOTV operation wins,” she said.
Georgia is one of a couple of states that require a candidate to win a majority of votes in order to be declared the winner.
The state has had two other Senate runoffs. The last one was in 2008, when Sen. Saxby Chambliss, a Republican, was held below 50% in the general election. Barack Obama was at the top of the Democratic ticket, and nearly 3.8 million people voted.
For the runoff, just 2.1 million voted.
Mr. Chambliss kept about 66% of his support, but his Democratic opponent lost nearly half of his supporters, delivering an easy win to the Republican.
Of course, the stakes weren’t so high in that election. Democrats were guaranteed control of the Senate, though the Georgia seat could have given them a 60-vote filibuster-proof majority.
Georgia now looks decidedly different from what it did in 2008.
For one thing, Mr. Biden appears to have won the state — the first time a Democrat has carried it in a presidential election since 1992.
Republicans went into elections last week with 53 Senate seats. As of Sunday, they were guaranteed to control 48 and were expected to win two other elections where vote-counting was slow.
If they prevail in those races, they will have 50 seats and the two Georgia seats in question. A Republican win in even one of the Georgia races would give the party control of the chamber.
If Democrats win both Georgia races, then presumptive Vice President Kamala D. Harris, as president of the Senate, would break any tie votes.
With those stakes, national interest groups that didn’t give the races in Georgia more than a nod during the general election are now expected to pour tens of millions of dollars into the campaigns.
The full panoply of Democratic groups, fearing their investment in Mr. Biden may be hampered by a Republican-led Senate, is leaning into the race. They include gun control groups, Democracy for America and causes championed by the likes of Sen. Bernard Sanders of Vermont and Rep. Alexandria Ocasio-Cortez of New York.
Democracy for America, which advocates for government-sponsored health care, was an early supporter of Mr. Warnock but now backs Mr. Ossoff, who campaigns as more of a moderate.
“Victories for Rev. Raphael Warnock and Jon Ossoff in their respective Senate runoffs would not only underscore the political revolution that has taken place in Georgia this year, it could save President-elect Joe Biden’s agenda from the brick wall of obstruction that Mitch McConnell is hoping to construct in the United States Senate,” said Charles Chamberlain, chair of Democracy for America.
Jeffrey Lazarus, a political science professor at Georgia State University, said he doubts the two Democrats tack far left over the next two months.
“Georgia isn’t a very liberal state in the aggregate, so the idea of winning votes by invoking prominent names in the progressive movement doesn’t play the same way down here as it does in, say, Massachusetts,” Mr. Lazarus said.
He said he does expect the Democratic candidates to wrap themselves in Mr. Biden, who has a reputation as a centrist.
Still, he said, it’s an uphill climb for both.
“I’m skeptical of Democrats’ chances in the runoff,” he said.