How old is 'too old' to be president?

RICHMOND, Virginia – One is 81 and already the oldest man to run the White House. His challenger - a spry 78 - was right behind him. And neither man seems ready to call it quits.

But President Joe Biden's shaky debate performance against his predecessor Donald Trump has reignited discussion about imposing an age limit on candidates seeking the highest office.

"There's no hard and fast rule about these things and there are people (who) would argue otherwise, but...there's a one in three chance that Biden won't make it through a second term and there's about a one in four chance Trump wouldn't," said Gary Schmitt, a senior fellow at the American Enterprise Institute, a conservative think tank.

Here's what to know about some of the constitutional and legal issues surrounding age limits and the U.S. workplace:

What are the requirements to run for federal office?

There's no maximum age limit for presidential candidates.

The U.S. Constitution says any president has to be a natural-born U.S. citizen, at least 35 years old, and must have lived in the country for a minimum of 14 years.

U.S. senators must be 30+ and members of the U.S. House have to be at least 25 years old.

More than half a century ago, Biden was once the new kid on the block: elected to the Senate at just 29 and turning 30 less than two months before he was sworn into office in 1973.

Could the U.S. impose a maximum age limit for presidents?

Setting a maximum age limit would require a constitutional amendment, which typically needs a two-thirds majority in both the House and the Senate and support from three in four states – a nearly impossible bipartisan hurdle in the current climate.

Plus, whatever age you pick is ultimately somewhat arbitrary, said Schmitt, who does back some sort of upper limit.

Already, candidates must be old enough to be trusted - but who is to decide on the right ratio of age to wisdom?

"You can't run for president until you're 35 – well, we both know brilliant people who are savvy and could well be very fine presidents when they're 32," Schmitt said.

U.S. Rep. John James, a Republican from Michigan, introduced a proposal last year to bar anyone aged 75 or older from serving as president, vice president or in Congress. It went nowhere.

Biden was 78 when he assumed the presidency and Trump was 70 - making them the oldest at their first inaugurations, with Ronald Reagan close behind at 69. President Reagan ended up winning a second term and left office at the age of 77.

Could an age limit violate equal protection laws?

The Age Discrimination in Employment Act (ADEA) protects people of 40 and above from age discrimination - though maximum age limits do exist for some high-risk jobs, such as air traffic controllers, firefighters and pilots.

"There (are) very, very few jobs that are not subjected to the ADEA, and … those are very specific jobs that require very specific skills," said Tracey Gendron, who chairs the Virginia Commonwealth University Department of Gerontology.

Gendron said too much of a focus on age misses the broader point of whether someone might be qualified for a job.

"The older brain actually gets better and better at certain things," she said.

"There are benefits of having someone in charge who really has the ability for rational, slow, strategic thinking and that comes with an older brain," Gendron said. "So having an age limit would, again, certainly eliminate those people and probably disenfranchise other people who would feel as if they're not included in the whole democratic process."

Are there age limits for other jobs or offices?

Some state courts across the country have mandatory retirement ages for judges, ranging from 70 to 90 years old.

Major corporations like Target and Caterpillar have gone the other way, lifting mandatory retirement ages or making exceptions that allowed aging CEOs to stay on longer.

Certain commercial airline pilots must leave the job at 65, and the Federal Aviation Administration (FAA) typically requires air traffic controllers to retire at 56. Some areas also impose maximum age limits for other strenuous jobs such as police officers or firefighters

What do U.S. voters think about setting an upper age limit?

Nearly four in five Americans favor maximum age limits for elected officials in Washington, D.C., according to a Pew Research Center survey released in 2023.

Though Trump is only three years Biden's junior, the age issue appears to be dogging the incumbent much more heavily.

Seventy-four percent of voters think Biden is "just too old to be an effective president," compared to 43% who said the same of Trump, according to a recent New York Times/Siena poll. 

Put on the defensive about his fading capacity, Biden has fallen back on variations of 'watch me' - alluding to his hectic daily schedule and his many achievements as president.

"You know, the idea I'm too old," he told MSNBC this week. "(I) created over 15 million jobs, 21 million insured (through the Affordable Care Act), beat big pharma, relieved student debt for 5 million people, first black woman (on) the court. So, I think I have a significant - a significant run. And that's how I'd measure me - measure me (on) what I've done."

(Edited by Lyndsay Griffiths)