Power  /  Visualization

Which Generation Controls the Senate?

A visual breakdown of the U.S. Senate by age.

About This Chart

The data used to populate this chart is sourced from the ProPublica Congress API, which itself is sourced from the congress-legislators github project.

Generational breakdown uses age brackets defined by the Pew Research Center, except for "Missionary Generation", which is defined by the Strauss–Howe generational theory:

Name: Birth Years
Missionary Generation: 1860-1882
Lost Generation: 1883-1900
Greatest Generation: 1901-1927
Silent Generation: 1928-1945
Baby Boomers: 1946-1964
Generation X: 1965-1980
Millennials: 1981-1996

Vacancies in the Senate are not uncommon, for instance when a Senator dies or resigns. The tiles on this chart use the Senator that was holding the seat at the beginning of the term, even if they didn’t hold the seat for the majority of the term. This is why Kelly Loeffler and Kamala Harris have tiles in the 117th congress.

The senator's age in a particular year is calculated for January 3rd of that year.

While playing around with this, one interesting trend I noticed is how the average age of a Senator has increased over the last seventy years. If you hover over a tile and then slide to the right, you can see how senators at the same percentile of age are now older than they used to be. For instance, a middle-of-the-pack Senator in 1947 was maybe 55 or 56-ish years old. Now, the middle seems to be 65 or 66, a whole decade older! Of course, it would be trivial to calculate and plot mean/median ages for each congress, but, c’mon, isn’t it more fun to explore the data this way?

The chart itself was programmed using D3. The colors use D3's built in Tableau color scheme.