HARRISBURG, Pa. >> Democrat John Fetterman wouldn’t commit to releasing his full medical records during a highly anticipated debate against Republican Mehmet Oz on Tuesday, but insisted he could serve Pennsylvania in the Senate and vowed to “keep coming back up” more than five months after experiencing a stroke.

Fetterman, Pennsylvania’s 53-year-old lieutenant governor, has acknowledged that he “almost died” after suffering a stroke in May. On Tuesday night, he spoke haltingly at times as addressed what he called the “elephant in the room.”

“I had a stroke. He’s never let me forget that,” Fetterman said of his Republican opponent. “And I might miss some words during this debate, mush two words together, but it knocked me down and I’m going to keep coming back up.”

He also quickly tried to go on offense by attacking Oz’s “gigantic mansions” and jabbing that “every time he’s on TV he’s lying.”

Fetterman insists he is prepared for the demands of the Senate as he continues to recover from the stroke. Independent experts consulted by The Associated Press before the debate said he appears to be recovering remarkably well. He used closed-captioning during the debate to help him process the words he hears.

Oz, a celebrity heart surgeon, ignored his opponent’s health early in the debate, though he has hammered Fetterman on the issue repeatedly during the campaign. On Tuesday night, Oz attacked Fetterman’s policies on crime, saying he is “trying to get as many murders out of jail as possible.”

“These radical positions extend beyond crime,” Oz charged.

While debates have rarely swayed elections in the modern era, the intense national interest in the primetime affair — particularly in Fetterman’s performance — suggested this debate could prove decisive in an election central to the Democrats’ urgent fight to retain their Senate majority.

For Democrats, there is no better pickup opportunity in the U.S. than the race to replace retiring Republican Sen. Pat Toomey in a state Biden narrowly carried in 2020.

For much of the year, it looked as if Fetterman was the clear favorite, especially as Republicans waged a nasty nomination battle that left the GOP divided and bitter. But as Election Day nears, the race has tightened. And now, just two weeks before the final votes are cast, even the White House is privately concerned that Fetterman’s candidacy is at risk.

Voting is already well underway across the state. As of Tuesday, 639,000 votes had already been cast.

“The debate looms very large, bigger than usual for a Senate debate,” said Republican activist Charles Gerow, a veteran of two decades of Sunday TV political talk shows.

The Pennsylvania Senate hopefuls faced each other inside a Harrisburg television studio. No audience was allowed, and the the debate host, Nexstar Media, declined to allow an AP photographer access to the event.

The meeting was the first and only major statewide debate this year in Pennsylvania, since Democrat Josh Shapiro and Republican Doug Mastriano couldn’t reach an agreement on terms for a gubernatorial debate.

Fetterman is a star in progressive politics nationwide, having developed a loyal following thanks in part to his blunt working-class appeal, extraordinary height, tattoos and unapologetic progressive policies. On Tuesday, the 6-foot-9-inch Democrat swapped his trademark hoodie and shorts for a dark suit and tie.

But Fetterman’s health has emerged as a central issue over the election’s final weeks, even as candidates elsewhere clash over issues like abortion, crime and inflation.

Oz had pushed for more than a half-dozen debates, suggesting that Fetterman’s unwillingness to agree to more than one is because the stroke had debilitated him. Fetterman insisted that one debate is typical — although two is more customary — and that Oz’s focus on debates was a cynical ploy to lie about his health.

Democrats noted that the televised debate setting likely would have favored Oz even without questions about the stroke.

Oz is a longtime television personality who hosted “The Dr. Oz Show” weekdays for 13 seasons after getting his start as a regular guest on Oprah Winfrey’s show in 2004. Fetterman, by contrast, is a less practiced public speaker who is introverted by nature.

“This was always going to be an away game for John Fetterman,” said Mustafa Rashed, a Democratic political consultant based in Philadelphia.

Fetterman asked for, and was granted, a closed-captioning system for the debate that displayed in writing everything said on a large screen behind the moderators.

The Fetterman campaign said in a memo ahead of the debate that the closed captioning would be “typed out by human beings in real time, on live TV,” warning that it could lead to time delays, transcription errors and miscommunication. “It is impossible to control and unavoidable,” the memo said.