Mapping The Gerontocracy

The passing of California Senator Dianne Feinstein at the age of 90 is throwing a spotlight on America’s political establishment, not only with the government narrowly escaping shutdown, but on questions of ageism, representation, and fitness for office.

Feinstein had a noteworthy career. As the longest-running woman in the Senate’s history, she served the nation’s most populous state.

Yet, as Visual Capitalist's Dorothy Neufeld details below, Feinstein’s growing health complications along with two incidents of Senate Minority Leader Mitch McConnell freezing while speaking this year highlight the growing trend of America’s aging leadership.

The above graphic shows the age of U.S. senators, by state as of October 5, 2023.

How the Age of U.S. Senators Breaks Down

Today, 66% of senators are over the age of 60.

While senators have historically been older than the American population, consider how the median age in the U.S. is 39 according to the 2020 U.S. Census, and the median age of the Senate prior to Feinstein’s passing was 65.

We can see in the below table how the Senate has become growingly older, influenced by longer lifespans and the increased likelihood of members running for re-election (and winning). In addition, members in the Baby Boomer generation, ages 58 to 77 years old, often have more resources and wealth to help secure their seat.

On the other end of the spectrum are nine senators under the age of 50, including Democrat Jon Ossoff of Georgia, at 36, and Republican senator J.D. Vance of Ohio, at 39. Laphonza Butler, 44, the newly appointed senator to replace Feinstein, also falls within this camp.

This trend of an older Senate may have policy ramifications.

Studies show that lawmakers’ identities can influence legislative behavior. Older members of Congress have been shown to have a higher likelihood of introducing legislation on prescription drugs and long-term care, and other issues affecting seniors.

Other studies show that racial minorities, women, and veterans are more likely to intervene in Congress in the interest of these groups.

Top U.S. Senators, by Time in Office

Along with the trend of an older Congress, the average number of years served has also increased.

Today, senators in the 118th Congress have served 11.2 years on average as of January 2023. Over the 20th century, turnover has decreased due to more senators seeking re-election, which stands in contrast to the Senate’s early history when turnover happened more frequently.

Below, we show the currently serving senators that have held office the longest, based on their time in both the Senate and the House:

Together, the top five U.S. senators have served a combined 216 years in office.