A new poll suggests that a vast majority of Americans — more than three-quarters of them — believe there should be maximum age limits for people serving in public office in America.

The poll, by CBS News and YouGov, found that 77 percent of those surveyed agreed with the statement that there should be age limits and that after politicians reach a certain age, they should not be permitted to hold public office any longer.

The sentiment was a bipartisan one, with 76 percent of Democrats agreeing with the statement and 79 percent of Republicans doing so. Slightly less than half thought the maximum age should be 70, and about a third said the maximum should be between 50 and 60 years of age. One in five said the maximum age should be pegged at 80.

The poll’s findings come amid increasing scrutiny of the age and health of leaders in both American political parties. Most Americans have told pollsters that President Biden is already too old to be president, much less fit for a second, four-year term. That would start in 2025, when he is 82 years old. Senators such as Mitch McConnell, who is 81, and Dianne Feinstein, who is 90, have also been under a microscope in recent weeks.

Speaking at a press conference in Vietnam Sunday after a two-day summit in India, Mr. Biden raised eyebrows with what was described as a “rambling” recital by many observers. During the course of the event, he described climate change as more frightful than nuclear war and those who don’t see it as an existential threat as “lying, dog-faced pony soldiers.”

Mr. Biden stammered when asked about his meeting with the Chinese premier and was cut off mid-sentence by his press secretary, who declared to the gathered journalists that the press conference was over. “I’m going to go to bed,” the president said before walking off the stage.

In the CBS survey, slightly more than half of the 2,335 respondents polled last week said the jobs of both senator and president are too demanding for someone older than 75. About 80 percent also said a public official above the age of 75 risks being out of touch with the times and being unable to satisfactorily perform his or her job. The sentiment was shared by voters of all ages, including those aged 65 and older.

A Pew Research survey of the current Congress found that while the median age of members of the House of Representatives has ticked down in recent years — to 57.9 years from 58.9 in the previous Congress — the median in the Senate continues to creep up. The current Senate’s median age is 65.3 years compared to 64.8 years in the 117th Congress.

There are now 16 U.S. senators above the age of 75, and another 18 are between the ages of 70 and 74. There are 43 members of the House aged 75 or older, and another 42 are between 70 and 74 years of age.

Scrutiny of Mr. McConnell increased two weeks ago after the Kentucky senator froze for the second time in recent months in the middle of a press conference in his home state. Mr. McConnell’s office later released a statement from the Capitol’s attending physician stating that the episode was not attributable to some sort of seizure disorder, stroke, or Parkinson’s disease.

A poll released Monday by Rasmussen suggests that an overwhelming number of Americans feel the same way about Mr. McConnell as they do about the president. Three-quarters of those surveyed said he should resign his leadership post in light of his apparent health issues. Only about 17 percent of those surveyed disagreed with the statement.