Analysis | America is older, and so is the Senate. That has repercussions.

When Sen. Dianne Feinstein (D-Calif.) announced in February that she planned to retire, I looked at the unique position she holds in the Senate: among the oldest senators ever to serve but representative of how the chamber itself is aging.

Since then, Feinstein’s prolonged absence from the Senate has drawn new, more critical scrutiny to her decision to serve out her term. The Democratic Party ostensibly has a two-seat majority in the chamber, but thanks to absences, including the prolonged one from Feinstein, it has had a majority of at least two votes on only 30 percent of votes that have been cast this year.

Again, though, this is a challenge that is likely to recur, for both parties. There’s a simple reason for that: America is getting older, and so the Senate is getting older. And getting older means more health problems that can lead to prolonged absences — or incapacity.

Using data from the open-source UnitedStates.io project and the Census Bureau, I looked at the age distribution of both the Senate and the over-30 population of the United States over the past 80 years. (The most recent year for which detailed data are available nationally is 2022, so I used every 10 years from 1942 on.) Only recently did a majority of the Senate pass the 60-year mark, evaluating the age of each senator when sworn in over the previous six years.

There has been a steady upward climb in the age distribution of the Senate since the 1982 measure. 1982 happens to be the first year on that chart in which baby boomers — those born between 1946 and 1964 — were at least 30 years old. The aging of the population since 1982 is a function of the aging baby boom, and the aging Senate is a function of the aging population.

You can see that, in 2022, a plurality of senators were in their 60s at the time they were sworn in. You can also see that the percentage of senators 80 and older is closer to the percentage of the U.S. over-30 population than at any time in the past half-century.

Why are there more Americans overall at the edges of those charts? Because younger people are less likely to be elected to the Senate, a chamber that tends to be occupied by people with previous experience in elective office. And because older people are often less interested in doing so or less able to.

I run the risk of being unfair here, so I won’t tread too far down the path. It is the case, though, that older people have slower recovery times from injury or illness. It is also the case that the incidence of dementia increases at advanced ages. That Americans are living longer than they did in the 1940s is good news, but there are limits to human activity that come into play well before people die.

With an older America comes an older legislature. And that means that elected officials might be expected to hit those limits more frequently — a challenge to any individual, but particularly a challenge to those who live their lives in the public eye.