How Old Is Too Old to Be President? An Uncomfortable Question Arises Again.

When Dwight D. Eisenhower weighed the pros and cons of running for a second term, one factor that concerned him was his age.

Arguing against a re-election campaign in his mind, he wrote in his diary in November 1954, was the need for “younger men in positions of the highest responsibility” at a time of “growing severity and complexity of problems that rest upon the president.”

He was 64 at the time.

Today the two leading candidates for his old job clock in at 77 and 81. Barring an unforeseen political earthquake, America seems destined to have a commander in chief well past typical retirement age for years to come no matter who wins in November. Donald J. Trump would be 82 at the end of the next term, and Joseph R. Biden Jr. would be 86.

Aging today, of course, is different than it was in the 1950s, and Eisenhower did decide to run again, serving out a second term leading an administration that historians credit as formidable. But he experienced multiple serious health scares in office that tested his Cold War presidency, and it seems reasonable to assume that the country could be confronted with similar issues between now and January 2029, when the next term will expire.

The issue of age was thrust back onto the front burner with the special counsel report on Mr. Biden’s handling of classified information that described the president as a “well-meaning, elderly man with a poor memory” who had “diminished faculties in advancing age.” The report came the same week that Mr. Biden on two occasions referred to European leaders who are, in fact, dead as if they were still around and mistakenly called the president of Egypt the president of Mexico.

Mr. Trump quickly sought to capitalize on the special counsel report, issuing a statement through an aide calling Mr. Biden “too senile to be president.” But Mr. Trump has suffered his own bouts of public perplexity lately, confusing the leaders of Hungary and Turkey, warning that the country is on the verge of World War II, saying that he defeated Barack Obama instead of Hillary Clinton and referring to his Republican primary challenger, Nikki Haley, as if she were Nancy Pelosi, the former House speaker.