You could call it an age-old question: How old is too old to hold public office?
Long-debated in American politics, it's come to the fore once again after an alarming moment last week when Senate Minority Leader Mitch McConnell appeared to freeze for half a minute while answering reporter questions, strikingly similar to another such episode in July.
Doctors tell ABC News that anyone who experiences similar symptoms -- regardless of their age -- should seek immediate medical attention. And McConnell's office has since released a statement that he's medically clear to work. But the episode has sparked renewed concern about the 81-year-old Republican leader's health after a March concussion -- and broader questions about the relatively advanced ages of some of the nation's most powerful elected officials.
Those questions also made headlines when Democratic Sen. Dianne Feinstein, now 90, returned to Capitol Hill this spring visibly frail and appearing disoriented after being sidelined due to a case of shingles that resulted in serious complications. Her monthslong absence prompted calls for her to resign earlier than her planned January 2025 exit.
MORE: Dianne Feinstein's Senate return highlights her sad decline amid swirl of political questions: ANALYSIS"It's more salient now than it ever has been before, and I think it's clearly because politicians are older than they ever had been before," Kevin Munger, a political science professor at Penn State University, said in an interview with ABC News.
The median age of Congress (59 years old) has been ticking upward for years -- and for the Senate it's 65, according to FiveThirtyEight.
While older members can be criticized for being out of touch, supporters say their seniority and experience enhances their influence.
Munger doesn't anticipate a significant generational turnover until the early 2030s.
But perhaps nowhere is the age question more debated -- and relatable to all Americans to what they see in their daily lives -- than when it comes to the presidency.
On Monday, appearing fired-up speaking at a Labor Day morning event before a friendly crowd of union workers in Philadelphia, Biden acknowledged, and then tried to downplay, the doubts.
"I tell you what, someone said, you know, that Biden he's getting old, man," he said. "I tell you what. Well, guess what -- guess what, I -- you know, the only thing that comes with age is a little bit of wisdom. I've been – I've been doing this longer than anybody and, I -- guess what, I'm gonna continue to do it with your help."
Now 80, Biden is the oldest sitting commander in chief in history. If reelected, he would be 82 when he starts his second term and 86 by the time it's over.
While his chief rival, former President Donald Trump, isn't far behind at age 77, his age gets relatively little attention compared to his legal situation, and Republicans are seizing on Biden's age as one of his biggest vulnerabilities heading into next year's presidential election.
Voters largely agree, polling shows.
A new Associated Press-NORC Center for Public Affairs Research survey found 77% of U.S. adults said Biden is too old to be effective for another term. In comparison, roughly half of U.S. adults (51%) said they thought Trump was too old to serve as president.
Even a majority of Democrats (69%) expressed concern about Biden's age, although a vast majority (88%) said they would still probably support him if he's the nominee.
"This is what we get when we prioritize partisan victory over everything else. Everything else fades into the background, and now we're in a situation where we're very likely to have the two oldest presidential candidates in history," Munger said.
A Wall Street Journal poll out over the weekend also found voters overwhelmingly -- 73% -- think Biden is too old to run for reelection, compared with 47% of voters who said the same of Trump.
Biden's age is the target of 2024 GOP candidates and his missteps and awkward moments have been routinely mocked on Fox News.
"There are plenty of folks who would like to weaponize age," said S. Jay Olshansky, a professor of public health at the University of Illinois at Chicago who criticized such comments as ageist.
"How old is too old? That's an unanswerable question," Olshansky said.
While the risk of cognitive decline rises as we get older, Olshansky stressed that people age at different rates and that heterogeneity -- human diversity -- must be taken into account.
"Some people make it out into their 80s and beyond very healthy, functioning cognitively at a very high level and there's some people who can't make it past their 50s and do very well," he said. "So, we have to recognize the great variability."
McConnell and Feinstein are not the only octogenarian members of Congress. Iowa Republican Sen. Chuck Grassley, 89, famous for jogging and challenging younger people to push-up contests, just won reelection to another term. California Democrat Rep. Nancy Pelosi, 83, kept reporters rushing to keep up with her brisk walk for years while she served as House speaker before stepping down from leadership.
When it comes to Biden, The New York Times reported in 2021 that he exercises regularly on a Peloton bike and lifts weights. He's seen biking around Delaware and last month the White House said he took spin and pilates classes while vacationing in Lake Tahoe, California.
But despite that, perhaps most noticeable now is how he appears to shuffle along at times, taking short, sometimes uncertain steps. Earlier this year, the president's physician, Dr. Kevin O'Connor, noted Biden's "gait remains stiff" in a memorandum summarizing on his physical, attributing how he walks in part to "significant spinal arthritis" and the impact of a broken foot and neuropathy in his feet.
He can stumble making remarks, and often coughs. (O'Connor said the president "experiences occasional symptoms of gastroesophageal reflux, primarily having to clear his throat more often.") He's had skin cancer and COVID-19.
MORE: Biden 'remains fit for duty,' White House doctor says after his 2nd presidential physicalAs questions have been raised more frequently about his age, Biden's retort has been: "Watch me."
And he's being watched.
In June, cable and network news gave heavy play to the moment he took a hard fall at the Air Force Academy commencement in Colorado, apparently after tripping over a sandbag.
He recently began using the shorter staircase that comes out of Air Force One's underbelly more frequently, rather than the taller stairs, on which he has taken tumbles more than once.
The president's later morning start to his day most days also has been highlighted.
"It was striking that he took so few morning meetings or presided over so few public events before 10 a.m.," journalist Franklin Foer reportedly writes in "The Last Politician," his forthcoming book. "In private, he would occasionally admit that he felt tired."
The White House had no comment on Foer's reporting but says it doesn't want to run away from Biden's age. To counter the growing questions and perceptions, the White House is embracing it as a positive.
"Joe Biden has achieved the strongest record of any modern President because of his experience, his drive, his judgment, and his values," White House spokesman Andrew Bates said in a written statement to ABC News. "We welcome a conversation about his age because it shines a light on those qualities and that historic record."
MORE: Biden's age a target for critics, issue for voters as he kicks off campaign: ANALYSISBates cited the Bipartisan Infrastructure Law, the administration's newly announced rule to make 10 prescription drugs subject to Medicare cost negotiations, and the president's work to rally NATO allies in defense of Ukraine, amid his multiple foreign trips.
Biden's team points to his surprise visit to Kyiv, Ukraine, in February amid that country's ongoing war with Russia, which included a 10-hour train ride from Poland to the Ukrainian capital, along with his striking deals with House Republicans.
"You've seen his stamina, whether it's in a war zone like Kiev, working a congressional rope line for hours, or refusing to give up on legislative breakthroughs long after what are now signature accomplishments had been written off as impossible in headline after headline," Bates said, adding, "So, yes, we're happy to have that conversation."
Part of Biden's strategy is to commonly make light of his advanced years.
Earlier this year at the White House Correspondents' Association Dinner, just four days after his reelection announcement, he joked he was friends with one of America's founding fathers.
"I believe in the First Amendment, not just because my good friend Jimmy Madison wrote it," Biden joked about the nation's fourth president who died in 1836.
"You call me old; I call it being seasoned," Biden quipped at the dinner. "You say I'm ancient; I say I'm wise."
At a campaign reception this summer Biden suggested, in jest, he has been serving in public life for nearly three centuries.
"I think I know as much about American foreign policy as anybody living, including Dr. Kissinger," Biden said referencing the former secretary of state. "That's what I've done my whole life -- for the last 270 years."
But Biden has also conceded his age, for many voters, will be a serious consideration.
"I respect them taking a hard look at it," Biden told ABC Chief White House Correspondent Mary Bruce in April after announcing his reelection campaign. "I'd take a hard look at it as well. I took a hard look at it before I decided to run."
In a country where the average age is 38.9 years old, polls show many Americans are, indeed, taking that hard look.