MIAMI — Senator Bill Nelson of Florida, a Democrat, conceded on Sunday that he had lost his re-election bid to Gov. Rick Scott, a Republican, bringing Florida’s turbulent midterm election to its long-delayed end after an unprecedented statewide recount.
Mr. Nelson telephoned Mr. Scott on Sunday afternoon to congratulate him, shortly after the conclusion of the manual recount showed that Mr. Scott had won the Senate race by 10,033 votes, out of more than 8.1 million cast.
Mr. Scott called for unity on Sunday, after the midterm elections revealed an electorate so closely divided that three marquee statewide races were decided by just a few tenths of a percentage point.
“Now the campaign truly is behind us, and that’s where we need to leave it,” Mr. Scott said. “We must do what Americans have always done: come together for the good of our state and our country.”
Mr. Nelson said in a video statement that “things worked out a little differently” then he had hoped.
“I by no measure feel defeated, and that’s because I’ve had the privilege of serving the people of Florida and our country for most of my life,” he said. “To all Floridians, whether you voted for me, or for my opponent, or you didn’t vote at all, I ask you to never give up this fight.” He did not mention Mr. Scott by name in the video.
A final certification of Florida’s vote tally is scheduled for Tuesday.
No politician in recent Florida history has proved to be as formidable as Mr. Scott, who can now boast of an unbeaten election record in the nation’s largest presidential battleground. He has triumphed in three out of three statewide contests — two for governor and one for senator, all by about 1 percentage point or less — thanks to his personal wealth and relentless campaigning.
His Senate victory was a relief not only to Mr. Scott but also to national Republican leaders who had feared that their supporters’ morale would plummet if, on the heels of a fairly dismal Election Day for the party, an apparent victory turned into one more loss. Florida could give Republicans a 52-to-47 margin in the Senate, a two-seat pickup for the 2018 cycle, if the party also wins a Nov. 27 runoff scheduled in Mississippi for a seat already held by the G.O.P.
President Trump has declared the midterms a great success for his party, but Republican strategists view the cycle as something of a disappointment, after hopes of gaining as many as four Senate seats dissipated with victories by Democrats in Montana and Arizona.
Though the Senate contest constituted the top of the Florida ticket, in the general election it drew less excitement and outside attention than the governor’s race between two young and unyieldingly partisan rivals, Ron DeSantis, a Republican, and Andrew Gillum, a Democrat. Mr. Gillum, who trailed Mr. DeSantis by a wider margin than Mr. Nelson did Mr. Scott, conceded his own loss on Saturday, two days after a machine recount in that race confirmed that Mr. DeSantis had won. Under Florida law, three statewide races — for governor, senator and agriculture commissioner — required machine recounts, but only the latter two were close enough after that to also require a manual recount.
Sunday’s results in the contest for agriculture commissioner contest showed Nikki Fried, a Democrat, ahead of Matt Caldwell, a Republican, by 6,753 votes, or 0.08 percent. In a statement on Sunday, Ms. Fried, who will become the only Democrat elected to statewide office in Florida, thanked Mr. Caldwell, who has yet to concede.
“It’s now time for us to come together and work in union to govern for the people of Florida,” Ms. Fried said. She campaigned on a nontraditional platform of making medical marijuana more accessible and tightening procedures to obtain concealed weapons permits.
The Senate race was bitterly fought from the start. Though Mr. Nelson, 76, was a three-term incumbent, he had less name recognition than Mr. Scott, 65, a multimillionaire former hospital executive who was completing his second term as governor. A centrist, Mr. Nelson, who was first elected to the State House in 1972, was not particularly exciting to the increasingly young, progressive Democratic base, and he never quite seemed comfortable seizing the spotlight.
Mr. Scott, for his part, carefully distanced himself from Mr. Trump in an election that turned heavily on voters’ dislike for the current administration. Over the course of his eight years as governor, he also tempered his Tea Party conservatism somewhat, shifting to support more moderate measures on guns and immigration. But he embraced Mr. Trump’s bombastic style after Election Day, when it came to claiming rampant fraud nobody could prove.
Several Florida Republicans allied with Mr. Scott fretted about the assertive former health care executive’s ability to adjust to being a junior member of a legislative body where he will have no executive authority. Mr. Scott is still deeply involved in the details of governing Florida — and has been particularly immersed in the process of creating a list of conservative judges for three vacancies on the state’s highest court, which his successor, Mr. DeSantis, will select.
Mr. Nelson and his lawyers had hoped that his weakness in the Democratic stronghold of Broward County, in South Florida, was simply a matter of machines failing to read ballots properly, a problem that a manual recount could have resolved. But a recount can’t produce votes if voters did not cast them, even if they failed to cast them by mistake. A visual review of those ballots this weekend showed that Mr. Nelson only picked up a few hundred votes.
History showed from the start of the recount that a victory for Mr. Nelson was the longest of long shots. No recount had ever overturned a lead as large as Mr. Scott’s. From 2000 to 2016, recounts reversed the results of only three statewide elections — one in Minnesota, one in Vermont and one in Washington — and the margins in those races were in the hundreds, not the thousands.
That did not stop Democrats from going to court over and over again since Election Day in attempts to get more votes counted. Although they did win one important victory — an extension for people who voted by mail whose signatures were rejected — the Nelson campaign faced a series of defeats that kept closing the circle on possible votes for him.
The math was simply never in Mr. Nelson’s favor.
Much like the recount in the infamous presidential election of 2000, this year’s recount in Florida, a process intended to reaffirm the will of the voters, has also exposed myriad flaws in the state’s election system, a concern for politicians and campaigns already looking ahead to the next election in 2020.
The litigious period since Nov. 6 has called into question how Florida handles ballots cast by mail, whether local elections supervisors are competently running their offices, whether statutory deadlines to complete recounts are too short and whether the machines now in use are even capable of conducting multiple statewide recounts.
As in 2000, much of the focus has been on South Florida, where the state’s most populous counties raced to count millions of votes. The fact that troubled Broward County appeared able to meet the deadline of noon on Sunday to file its manual recount tally — after having missed the machine recount deadline on Thursday by two minutes — prompted a round of applause inside the county elections office in Lauderhill, Fla. Broward transmitted its results to the Florida division of elections in Tallahassee, the state capital, by 11:09 a.m.
“When you sign that, I’m going to collapse,” said Joseph D’Alessandro, the county’s head of elections operations.
Dr. Brenda C. Snipes, the county elections supervisor, who faces calls for her ouster over her handling of the election and recount, told the local CBS affiliate that the manual recount was “fast and furious.” Now, she said, she planned to “turn off the lights and lock the doors.”
Broward’s machine recount, completed on Thursday, came up more than 2,000 votes short of initial tallies, which left the canvassing board in the position of having to decide which set of results to use. Dr. Snipes, an elected Democrat, said the missing ballots were probably misfiled with another stack of ballots.
“The ballots are in the building,” she said on Saturday. “I know that sounds trite — it sounds foolish.”
Lawyers representing candidates in the close races pointed out that it did not help if the ballots were in the building but not counted.
Officials decided to submit the original tally, completed on Nov. 10, in addition to whatever overseas and military ballots had been received since then.
The issue was of concern to the political parties, because the machine recount results showed Mr. Scott gaining some 700 votes.
The Florida secretary of state’s office, which supervises elections statewide, initially said the machine recount results would be accepted, regardless of the shortfall. But on Sunday, a spokeswoman for Secretary of State Ken Detzner suggested that it would be acceptable for Broward to use the original vote count, because the board had the obligation to “make sure that every valid vote is counted” when submitting their official results.
In neighboring Palm Beach County, which has not upgraded its vote-counting machines in 11 years, the elections supervisor, Susan Bucher, acknowledged last week that she would be unable to meet the Sunday deadline for all races. Instead, her office completed the manual recount in the Senate race and, as ordered by a federal judge, spent Sunday reviewing ballots in a State House race where the candidates were separated by a mere 37 votes.
Mike Caruso, a Republican in that race, found himself in the lead by 32 votes after that review, and said he was heading home to pack for Tallahassee, where he expects to be sworn in on Tuesday. Jim Bonfiglio, his Democratic opponent, noted he has 10 days to review the results and consider any further legal action. “We were tied after the machine recount,” Mr. Bonfiglio said.
Under state law, Palm Beach will have to eventually complete the manual recounts in the races for governor and agriculture commissioner, even if the results will come after Tuesday’s certification deadline. Based on how long it took the county to recount the Senate race — more than five days’ worth of work — the process could continue into mid- to late December, Ms. Bucher, an elected Democrat, said on Friday. She added that her office will resume normal business hours for the remainder of the recount.
Hillsborough County, home to Tampa, also did not submit its machine recount results, which showed a drop-off of more than 850 votes from initial tallies.