Back on NewsNation, neurologist Dr. Huma Sheikh of Mount Sinai Hospital joined Chris Cuomo to discuss Fetterman's medical situation.

"I think, for him, the major issue is his production of language, his ability to express his thoughts and elaborate on them. I think we saw during the debate that he had difficulty with fluency ... When he had to come up with spontaneous answers to some of the questions or responses, he repeated a lot, he made what we call paraphasic errors, where you say a word that is similar to what you're actually trying to say."

"It's hard to tell from this how much his comprehension was impaired ... but definitely being able to express himself and elaborate on his thoughts was difficult."

When Cuomo asked if Fetterman's condition could improve, Dr. Sheikh answered: "It depends ... essentially, what we know is that in the first 3-6 months is where you see the most improvement. There can be some improvement over the next year, but I think -- he's about six months out now, this happened in May. So I think if he was doing therapy right after his stroke, this is probably where he has improved to the most."

The Fetterman campaign has put out a statement saying they're "thrilled" with their man's debate performance.

"He did remarkably well tonight – especially when you consider that he’s still recovering from a stroke and was working off of delayed captions filled with errors," they say.

Of course, the use of such a closed-captioning system in this debate at all was an extraordinary concession to the lieutenant governor's campaign.

Some political pundits are revisiting the controversy over an interview Fetterman gave to NBC News earlier this month.

The reporter who conducted the sitdown, Dasha Burns, was criticized by some of her colleagues -- and accused of being "ableist" by Fetterman's own wife -- for noting that "just in some of the small talk prior to the interview, before the closed captioning was up and running, it did seem that he had a hard time understanding our conversation.”

This is the debate answer from Fetterman that will likely feature prominently in GOP attack ads over the next two weeks.

Listen to the Democratic candidate attempt to explain away his stated opposition to fracking:

Oz put Fetterman on blast during the debate for refusing to meet him onstage until Tuesday night, just two weeks before Election Day and after hundreds of thousands of Pennsylvanians had already cast their ballots.

"You haven't shown up on the campaign trail, you haven't answered questions from voters -- not once on the campaign trail," Oz told Fetterman.

"And this is the only debate I could get you to come to talk to me on and I have to beg on my knees to get you to come."

Reporter Al Weaver of The Hill tweets that Democrats he's spoken to are asking why Fetterman's campaign agreed to go ahead with tonight's debate.

"No one I'm talking to on the left has a good thing to say about what just took place," he tweets.

Reaction to the debate is already rolling in, most of it concerning Fetterman's capability.

Time magazine writer Charlotte Alter, who posted a lengthy pre-debate Twitter thread warning that the Democrat was likely to struggle, tweets:

After stumbling through his closing statement, Fetterman earned a rebuke from the moderator by talking over Oz's finishing remarks.

"You want to cut Social Security!" the Democrat yelled when Oz spoke about talking to seniors who told him that their Social Security checks weren't going far enough because of inflation.

Oz said that his experience as a doctor listening to patients would translate well to hearing from voters about the issues affecting them. The candidate said that he was “the living embodiment of the American dream” and the candidate of change.

Earlier in the night, Oz pressed Fetterman on why he hasn’t apologized for pressing a shotgun against the chest of an unarmed black man who was jogging in Braddock, Pennsylvania in 2013.

Oz suggested that Fetterman may have “broken the law” during the incident.

"Everybody in Braddock, an overwhelmingly majority community of black community all understood what happened …and nobody believes that it was anything about me making a split-second decision to defend our community," Fetterman said.

"Why not apologize?" Oz asked before the moderator intervened.

NewsNation's 9 p.m. host gives his first read after the debate wraps: "John Fetterman struggled."

"He clearly is dealing with health issues that affect his ability to process and his ability to speak," Cuomo tells Leland Vittert. "Clearly, fitness for office is going to be on the table."

"That may not be fair, to some, for me to say, but if the voters aren't talking about it, I'll be shocked."

In the final question of the debate, Fetterman and Oz are asked whether they will be rooting for the Pittsburgh Steelers or Philadelphia Eagles when they play on Sunday.

Fetterman says the Steelers.

Oz, who was accused by Fetterman of being a Dallas Cowboys fan earlier this month: "I'll be at the game, and rooting for my Eagles."

"Fly, Eagles, Fly," he sang, looking rather sheepish.

Fetterman said he supports a "bipartisan solution" to the border crisis as a record number of migrants have crossed into the United States this year.

"I believe that a secure border can be compatible with compassion," Fetterman said on the stage. "I believe we need a comprehensive and bipartisan solution for immigration.

"I don't ever recall in the Statue of Liberty did they say 'Take our tired, huddled masses and put them on a bus and use cheap political stunts about them,'" he said.

Fetterman also took a shot at Oz, pointing out that his family received the the largest fine in ICE history -- $95 million -- over a scheme to knowingly employ illegal immigrants.