David McCormick Concedes to Dr. Oz in the G.O.P. Primary for Senate in Pennsylvania

David McCormick, a former hedge fund executive, conceded the exceedingly close race for the Republican nomination for Senate in Pennsylvania on Friday to Dr. Mehmet Oz, the celebrity television physician, with a statewide recount underway and no official race call.

Dr. Oz had a lead of fewer than 1,000 votes, or .07 percent, before the county-by-county recount began last week. The unexpected early concession — five days before the recount’s full results were to be released — was a recognition that Mr. McCormick had gained only handfuls of votes so far and faced an insurmountable hurdle in making up his deficit.

His decision sets up one of the most pivotal contests of the midterms, a November election between Dr. Oz and the Democratic nominee, Lt. Gov. John Fetterman.

“We spent the last 17 days making sure every Republican vote was counted,” Mr. McCormick said in an appearance in Harrisburg with supporters on Friday evening. “But it’s now clear to me that with the recount largely complete, that we have a nominee. And today I called Mehmet Oz to congratulate him on his victory.”

The primary initially produced a photo finish in which both campaigns’ calling for all votes to be counted vividly contrasted with how Republican supporters of former President Donald J. Trump reacted to his loss in Pennsylvania in 2020, when he and his allies tried to block the counting of ballots beyond Election Day.

Mr. Trump, who endorsed Dr. Oz, urged him the day after the election to follow his own conspiratorial script — he still maintains the presidential election was “stolen” — and declare victory before all the votes were in.

Dr. Oz, the longtime host of “The Dr. Oz Show” on daytime television, mostly ignored the advice. But as the recount began on May 27, he declared himself the “presumptive” nominee. The recount was ordered by Leigh M. Chapman, the state’s acting secretary of the commonwealth, and was triggered automatically by Pennsylvania law because the gap between candidates was under 0.5 percent.

Armies of lawyers for the candidates challenged small batches of provisional ballots in front of county election boards, sought hand recounts in certain precincts and went to court, scrapping over every vote. Mr. McCormick, who led his opponent on mail ballots, sued to include 850 or so mail-in votes that were received on time but did not have voters’ handwritten dates on the envelopes. Although he received a favorable ruling from the Commonwealth Court of Pennsylvania, it was clear that there just weren’t enough outstanding votes under any scenario for Mr. McCormick to prevail.

Suspense around the race for weeks deflected attention from Mr. Fetterman, who suffered a stroke May 13, days before the election, leading to a hospital stay and the implantation of a pacemaker and defibrillator in his heart. Mr. Fetterman’s absence from the campaign trail ever since and his refusal until Friday to offer more than scant details of his condition raised questions about his ability to campaign in the general election.

Mr. Fetterman, 52, revealed on Friday that he had “almost died” after ignoring for years a doctor’s warning that his heart’s pumping was diminished. His cardiologist made public a diagnosis of cardiomyopathy, which makes it harder for the heart’s muscles to pump. Ramesh R. Chandra, the cardiologist, said if Mr. Fetterman follows his instructions and takes his health seriously this time, “he should be able to campaign and serve in the U.S. Senate without a problem.”

The November election holds high stakes for both parties: Pennsylvania is probably Democrats’ best chance to add a seat to their fragile 50-50 control of the Senate, in which Vice President Kamala Harris holds the tiebreaking vote. With Senator Patrick J. Toomey retiring, the seat is the only G.O.P.-held open Senate seat in a state that Joseph R. Biden Jr. won in 2020. For Republicans, retaining it would ease their path to a Senate majority in a year when the political climate is strongly in their favor.

In a statement after Mr. McCormick’s concession, Dr. Oz said, “Now that our primary is over, we will make sure that this U.S. Senate seat does not fall into the hands of the radical left, led by John Fetterman.”

Dr. Oz, 61, who won Mr. Trump’s endorsement in large part because of his television charisma, was never fully embraced by core Trump supporters, as evidenced by the closeness of the race. At a rally Mr. Trump held in Pennsylvania 11 days before Election Day, boos greeted the mention of Dr. Oz’s name.

Mr. McCormick, a West Point graduate and the former chief executive of Bridgewater Associates, the world’s largest hedge fund, was more competitive than polls and many political experts had expected. In part that was because of Dr. Oz’s history of espousing liberal views, notably on abortion and transgender issues, which made him toxic to some conservatives.

Hesitance to embrace Dr. Oz by the Trump-centric base allowed a late surge by a hard-right candidate, Kathy Barnette. On Election Day, when she finished third with about 25 percent of the vote, she appeared to have siphoned grass-roots Trump supporters from Dr. Oz. She did so after declaring “MAGA does not belong to President Trump,” and despite Mr. Trump’s dismissal that Ms. Barnette, who has a history of homophobic and anti-Muslim remarks, “will never be able to win the general election.”

Dr. Oz and Mr. McCormick, both first-time candidates, worked hard to transform themselves from members of the East Coast elite, with middle-of-the-road politics, into credible champions of the MAGA movement.

Dr. Oz is a professor emeritus of surgery at Columbia University, but he called for the firing of Dr. Anthony S. Fauci, the government’s top infectious disease expert. He pledged to oppose nearly all abortions, despite having once held the opposite view. And on the eve of the election, he held a telephone town hall with the gun-rights absolutist Ted Nugent, even though he once helped write columns that called for gun controls.

Mr. McCormick, an Iraq War veteran who had criticized isolationism and backed an occasional Democrat, was quoted during the campaign as opposing “the weakness and wokeness that you see across the country.”

Mr. McCormick and his allies attacked Dr. Oz as a “Hollywood liberal” and for having served in the Turkish army as a dual citizen. Dr. Oz said he would give up Turkish citizenship if elected to the Senate.

Dr. Oz was also criticized as a carpetbagger who had moved to Pennsylvania to run for office. The American-born son of Turkish immigrants, Dr. Oz received his medical degree and a business degree from the University of Pennsylvania in the 1980s. His career was spent in New York, and for three decades, he lived in Northern New Jersey.

He only registered to vote in Pennsylvania in 2020 and has said that around the same time, he moved to a home owned by his in-laws in Bryn Athyn, Pa., a Philadelphia suburb. Last year, he and his wife, Lisa, bought a home nearby, according to a financial statement he filed in April, which put his personal fortune between $76 million and $300 million. If elected, he would be one of the wealthiest members of the Senate. He has already poured $12 million of his own money into his quest.

Both Dr. Oz and Mr. McCormick competed aggressively for Mr. Trump’s endorsement. In deciding on Dr. Oz less than six weeks before the election, the former president cited the popularity of the long-running “Dr. Oz Show” with women. Women “are drawn to Dr. Oz for his advice and counsel,” Mr. Trump said. “I have seen this many times over the years.”

Though “The Dr. Oz Show” has been criticized for a long history of offering viewers dubious medical advice, Mr. Trump was politically on-target about the electoral importance of women, especially in the suburbs. They have been key swing voters in recent Pennsylvania elections, notably in Mr. Trump’s defeat in 2020.

Blake Hounshell contributed reporting.