Fetterman, 53, explained that sometimes he stumbles over his words and has “auditory processing” issues. He asked rallygoers to raise their hand if they or someone they love had dealt with a serious health issue. Nearly every hand went up.

Since he suffered a stroke in May days before the primary, Fetterman and his allies have sought to make his recovery a lesson in empathy. The campaign has shared messages from people who say Fetterman inspired them to prioritize their own health. After his event Saturday, Fetterman knelt and spoke with a woman in a wheelchair who had also suffered a stroke.

Republicans, including Fetterman’s opponent, Mehmet Oz, have made the aftermath of the stroke central to their attacks against him. Some have called attention to his verbal struggles, reliance on closed captioning and summer absence from the trail. The Republican National Committee last week shared a montage of Fetterman’s verbal stumbles with the caption, “Does it sound like Fetterman is fit for office?” Oz has suggested Fetterman has something to hide, recently tweeting: “John Fetterman won’t answer questions from voters, he won’t debate more than once, and he won’t be honest about his health.”

Now, in the final weeks of one of the most consequential and competitive Senate races in the country, Fetterman’s health has become a focal point for both campaigns.

The Fetterman campaign has declined repeated requests to interview his doctors or review updated medical information beyond what it has previously released. The last medical information from a doctor made public by the Fetterman campaign came in a letter from his cardiologist on June 3, explaining that surgery conducted 17 days earlier to install a defibrillator was to treat a previously undisclosed diagnosis of cardiomyopathy, and not for atrial fibrillation (A-fib) as the campaign originally claimed.

Recently, after an NBC News reporter in Fetterman’s first in-person interview since his stroke questioned whether he had understood her without captioning, disability advocates and Fetterman supporters rallied to his defense. The campaign released a TV ad last week that shows Fetterman with his family at home, where he discusses his stroke and how it made him appreciate what really matters.

In a statement, Fetterman spokesman Joe Calvello said in part, “John is clearly sharp and healthy, and he also still has a lingering auditory processing issue that his doctors expect will go away.” The campaign declined to make Fetterman available for an interview.

Fetterman’s team has said he is fit to serve in the Senate and continues to improve. He has picked up the pace of campaign events and recently took questions for nearly an hour in a live interview with a local news outlet, with few verbal stumbles. His rally remarks are longer than when he first returned to the campaign trail in the summer. He continues to work with a speech therapist and blocks time off nearly every day for a several-mile walk, according to a person with knowledge of his activities who spoke on the condition of anonymity to more openly discuss Fetterman’s recovery.

Four top neurologists consulted by The Washington Post who are not treating Fetterman said he appears to have recovered well from a serious stroke with no obvious long-term effects other than his acknowledged difficulty understanding spoken language and finding words. Two based their assessments in part on reviewing the NBC News interview, while two others based their commentary on a review of his symptoms.

All the physicians interviewed for this story stressed that they are not caring for Fetterman and don’t have access to his medical records, cognitive tests or images of his brain, so they couldn’t speak conclusively about his specific case.

“It won’t get worse,” said Lee H. Schwamm, the C. Miller Fisher chair of vascular neurology at Massachusetts General Hospital in Boston. “It could recover in weeks to months, or it could recover in a year, or it could not recover any further.”

Fetterman gestured equally with both hands during his interview with NBC News, said Wade Smith, a professor of neurology at the University of California at San Francisco who watched the session. Both sides of his face moved equally well and in public he is walking without the use of a cane or other support, Smith said. All are signs he is not suffering other damage typical of a major stroke.

Republicans said they are not satisfied with the level of information Fetterman has shared about his health and are using it to advance a larger argument against his candidacy. “I’m of the opinion he has not been very transparent and forthright about that situation,” said former Republican congressman Charlie Dent of Pennsylvania, who is supporting Oz. “It seemed they understated the problem initially.”

Fetterman won the Democratic nomination days after the stroke without fully disclosing the extent of his physical condition. He revealed more than two weeks later that he had been diagnosed in 2017 with cardiomyopathy that decreased the amount of blood his heart could pump and had failed to take his medications and follow up with a doctor.

The June letter released by Fetterman’s doctor, Ramesh Chandra, said, “The prognosis I can give for John’s heart is this: if he takes his medications, eats healthy, and exercises, he’ll be fine. If he does what I’ve told him, and I do believe that he is taking his recovery and his health very seriously this time, he should be able to campaign and serve in the U.S. Senate without a problem.”

During an interview with the PennLive editorial board, Fetterman defended not releasing more recent medical records. “If anything changed I would have updated that,” he said.

Jeffrey Teuteberg, section chief for heart failure for Stanford Medicine, said that people with weakened hearts have a wide range of outcomes, from those with few or no symptoms such as breathlessness to those with severe symptoms that include fluid retention and inability to tolerate medications.

Oz, 62, has released three letters written by his doctor in 2014, 2018 and 2022 that describe his health as “excellent,” including a nearly ideal body mass index of 25. He has “borderline elevated” cholesterol, but because of his favorable ratio of “good” cholesterol to “bad” cholesterol was not prescribed medication such as a statin. A polyp was removed from his colon in 2010. Follow-up a year later was normal.

After speaking for more than 20 minutes without a teleprompter here Saturday, Fetterman came into the crowd to shake hands and pose for selfies with supporters, smiling and nodding as he moved between them. When he saw Mary Battle, 70, an Air Force veteran who fixed jets during the Vietnam War, in a wheelchair, he knelt down to her level. She had a mini-stroke three months ago, she said. She gifted him miniature guardian angel charms to watch over him.

“So, I know where he’s coming from,” Battle said. “I know how hard it is to get the words to come together right, so I’m totally in sync with him.”

Earlier in the day, Fetterman made brief remarks at a health-care union rally in North Philadelphia. When he stumbled over the word “workforce,” a woman yelled out, “Take your time, baby.”

Zelma Carroll, 55, a certified nursing assistant, said, in her opinion, he looked physically weakened but mentally strong.

“I honestly think he’s taking every strength he has to come here,” she said. “He showed up for us. He knows his purpose.”

Still ahead is a live, in-person debate between Fetterman and Oz set for Oct. 25. Fetterman plans to use a closed-caption system during the debate, as he has during recent interviews, to compensate for his auditory issues. Disability advocates said those type of accommodations should be normalized rather than viewed as a detriment.

“Once someone with an auditory processing problem has gotten the information, what they do with that information is as healthy as it would have been through any other mechanism,” said Brooke Hatfield, an associate director at the American Speech-Language-Hearing Association. “The decisions they make, the way they use that information or analyze that information and what they do with it isn’t an impaired process.”

On Capitol Hill, captioning accommodations have been provided, both to witnesses who come to Congress to give testimony and to staff workers such as David Bahar, a deaf former legislative assistant to Washington Gov. Jay Inslee (D) during Inslee’s time in the House of Representatives.

Bahar recalled that he was able to receive real-time transcription services in meetings, hearings and on the House floor. Bahar also pointed out that there are already television screens in the Senate floor gallery, where visitors can follow along with a live recording of discussions on the floor that includes on-screen captions.

“If they can provide that, they can figure out how to provide captions on the Senate floor as well,” he said.

Sarah Blahovec, a disability civic engagement expert, voiced frustration regarding what she sees as a stigmatization of cognitive disabilities for politicians in both parties. “It’s discourse we see all the time,” she said. “We’re focusing on one thing in exclusion of all other things that could or could not make them qualified to run for office.”

Sen. Robert P. Casey Jr. (D-Pa.) said he believes Fetterman has made “remarkable” progress, based on several conversations he has had with him in the past few months. Casey said Fetterman demonstrated his ability to understand when someone was talking to him and respond accordingly. In smaller meetings, he said, Fetterman “seems to be just fine.” But Casey wouldn’t speculate on whether Fetterman will fully recover from his auditory processing issues by January.

Other politicians, such as former senator Mark Kirk (R-Ill.), Sen. Chris Van Hollen (D-Md.) and Rep. Anthony G. Brown (D-Md.), have had strokes of varying degrees of severity, but all returned to work.

Kirk faced a grueling recovery, returning to the Senate in early 2013, about a year after his stroke. He later lost his 2016 reelection bid to Sen. Tammy Duckworth (D-Ill.), who was a House member at the time. In an interview Friday, Duckworth said that she did not focus on Kirk’s stroke during her campaign against him and that he remained effective until his last day in office. She said the focus on Fetterman’s stroke recovery is concerning, because accommodations are made for other lawmakers on a routine basis.

Rep. Jim Langevin (D-R.I.), who has served in office for two decades, was the first quadriplegic to serve in the U.S. House and remembers facing doubts about his ability to do the job because of his disability, he said.

“There was this undertone of ‘Can he do his job? Is he going to be able to effectively serve?’ ” he added.

He also recalled when former senator Tim Johnson (D-S.D.) suffered a brain hemorrhage in 2006 while in office. Johnson was initially in critical condition and later required months of rehabilitation to work on his speech and mobility issues. But Johnson eventually returned to work and was able to serve as chairman of the Banking Committee. Johnson was still able to do his job well with some accommodations, Langevin recalled. Johnson ran for reelection in 2008, and his opponent raised questions about his mental fitness. Johnson won by a wide margin.

At a recent focus group conducted by Rich Thau, a market research executive who has run a nonpartisan “Swing Voter Project,” 13 voters who supported Donald Trump in 2016 and Joe Biden in 2020 were asked about Fetterman’s health. Most said it wouldn’t factor into their support for him and expressed general concern for his overall health.

A Fox News poll released at the end of September asked if Pennsylvania voters were concerned that Fetterman “may not be healthy enough to carry out the job of senator effectively.” Forty-three percent said they weren’t concerned at all, 24 percent said they were extremely concerned, 10 percent said they were very concerned, and 18 percent said they were somewhat concerned.

At the Saturday rally, where raised hands affirmed attendees’ experience with major health challenges, Fetterman told the crowd, “I certainly hope that you did not have a doctor in your life making fun of it or telling you that you aren’t able to work or fit to serve.”

Bernstein and Morris reported from Washington. Paul Kane contributed to this report.