In the days since Joseph R. Biden Jr. was declared the winner in the presidential contest, the vote counting and reporting in states across the country have continued and are helping to clarify what the Senate will look like in 2021.
Democrats did not get the sort of blue wave they had hoped for, and their paths to flipping the Senate have significantly dwindled. In an election cycle in which President Trump ran much closer to Mr. Biden than many of the polls had predicted, Republicans appear poised to hold on to all but two of the roughly dozen seats that were thought to be competitive — and they flipped one seat held by a Democrat.
Two critical senate races in Georgia are headed to a runoff, a third race in Alaska, where the Republican candidate is significantly ahead, and a fourth race in North Carolina where the Democratic challenger has conceded, have all yet to be formally called.With the Alaska senate race likely to wind up in the Republicans’ column, it appears that Democrats’ only path to a senate majority will require winning both of Georgia’s senate seats.
Here is a quick summary of what has happened in Senate races across the country.
What Democrats needed to happen
Entering Election Day, Republicans held a three-seat advantage over Democrats in the Senate. That meant that in order for Democrats to take control of the chamber in 2021, they needed to flip at least three seats — and most likely four — assuming they also won the White House.
If Democrats were to pick up three seats, then Kamala Harris, as vice president, would be able to break a 50-50 tie in the Senate. But Senator Doug Jones, Democrat of Alabama, was widely expected to lose his race in the deep red state, so realistically, most Democrats expected they would have to flip a fourth Republican seat.
In that scenario, Democrats also had to defend the other 11 seats held by Democratic incumbents that were up for grabs this cycle, including one in the battleground state of Michigan.
What actually happened
The Democrats flipped two seats, in Arizona and Colorado, and the Republicans flipped one, Mr. Jones’s. That leaves Democrats, at least for the moment, with a net gain of just one seat — far short of what they needed .
As of Tuesday, Republicans have secured 49 seats in the next Senate, and Democrats, combined with the two independent senators who caucus with them, have secured 48.
The two races in Georgia are both headed to a Jan. 5 runoff because none of the candidates received 50 percent of the vote, the threshold under Georgia law to win outright. If a Republican wins either of the races in the traditionally conservative state, the party will maintain control of the Senate.
The Democrats held onto the other 11 seats they were defending, including in Michigan, where the Democratic incumbent, Gary Peters, narrowly prevailed.
Here is a state-by-state look at the Senate races played out.
Mr. Jones earned his Senate seat in a deeply red state after winning a special election in 2017 against Roy S. Moore, a Republican accused of sexual misconduct.
As expected, Mr. Jones lost by a wide margin to Tommy Tuberville, a Republican and former college football coach who has aligned himself with Mr. Trump.
As the polls had predicted, Mark Kelly, a former astronaut and retired Navy captain, defeated Senator Martha McSally, the Republican incumbent in Arizona. Mr. Kelly built a national profile as a gun safety advocate after his wife, former Representative Gabrielle Giffords, was seriously injured during a mass shooting in 2011. He ran as a pragmatic outsider and leaned hard into his biography on the campaign trail.
It was a second loss for Ms. McSally, who failed in her first run for Senate in 2018 but was then appointed by Gov. Doug Ducey to the seat left vacant by the death of Senator John McCain.
The polls were similarly accurate in predicting that former Gov. John Hickenlooper would defeat Senator Cory Gardner in Colorado. Mr. Hickenlooper, who had made an unsuccessful run for the Democratic nomination for president in 2019, handily defeated Mr. Gardner by roughly nine percentage points in a state that is increasingly tilting to the left and that went for Mr. Biden over Mr. Trump.
Iowa, Montana and South Carolina
Though Iowa, Montana and South Carolina are all traditionally right-leaning, polls had shown tight Senate races in those states, and the Cook Political Report had rated each a tossup. But come Election Day, Republicans easily won each race.
In Iowa, Senator Joni Ernst, the Republican incumbent, dispatched Theresa Greenfield, her Democratic challenger, by 6.6 percentage points. In Montana, Senator Steve Daines, the Republican incumbent, won by more than 10 percentage points against Steve Bullock, Montana’s two-term Democratic governor.
And in South Carolina, Senator Lindsey Graham, a Republican and the chairman of the Senate Judiciary Committee, survived a challenge by Jaime Harrison, a former chairman of the state’s Democratic Party, winning by 10.3 percentage points.
Perhaps no Senate race result proved as befuddling to Democrats as the one in Maine, where Senator Susan Collins, the Republican incumbent, brushed aside her Democratic challenger, Sara Gideon.
The race was one of the most difficult in Ms. Collins’s career. She faced extraordinary sums of Democratic money and anger over her decision to confirm then-Judge Brett M. Kavanaugh to the Supreme Court, and polls had her trailing Ms. Gideon, a formidable opponent who is the speaker of Maine’s House, for much of the race.
But it did not end up being all that close: As of Tuesday, Ms. Collins’s margin of victory over Ms. Gideon stood at nearly 8 percentage points.
Democrats were also deeply disappointed by the outcome in the North Carolina Senate race, where Senator Thom Tillis, a first-term Republican, appeared to have narrowly edged out his Democratic opponent, Cal Cunningham, a former state senator and an Army reserve officer, who conceded the race on Tuesday. Though there has been no official call, Edison Research reported that Mr. Tillis was leading in the race by just under 100,000 votes.
Like Ms. Gideon in Maine, Mr. Cunningham had a lead in the polls heading into Election Day. The race concluded with two significant developments: Mr. Tillis contracted the coronavirus, and Mr. Cunningham became mired in a scandal over romantic messages he had sent to a woman who is not his wife. While it was not immediately clear what effect, if any, those developments had on voters, as of Tuesday, Mr. Trump also held a considerable lead in North Carolina, which may have helped buoy Mr. Tillis.
What happens next
There were two Senate races held in Georgia both of which are headed to runoffs in January.
One of the races involves Senator David Perdue, a first-term Republican, who was trying to hold off Jon Ossoff, the Democratic nominee. Mr. Perdue’s share of the vote dipped below 50 percent last week as more ballots were tallied, forcing a showdown in January.
In the other race, the Rev. Raphael Warnock, a Democrat, and Senator Kelly Loeffler, the Republican incumbent, finished first and second in a special election that featured 20 candidates. Neither amassed 50 percent of the vote, and so, like Mr. Perdue and Mr. Ossoff, they will now go head-to-head on Jan. 5.
The pair of contests will most likely determine which party controls the Senate.