The Disproportionate Representation of Small States in the U.S. Senate

We have all seen the familiar map of red, blue, and purple states. I’ve reproduced this map with a focus on U.S. Senators, designating red and blue for states which have two Republican Senators or two Democrat Senators respectively. States with one Democrat and one Republican are coded purple. Because the 116th Congress (which ends next week) had two independent senators, one from Maine and one from Vermont, I have coded these slightly differently. In Vermont, one senator is a Democrat; the other is Independent, but caucuses with the Democrats. So, I have coded the state as a light blue. In Maine, one senator is a Republican; the other is Independent, but caucuses with the Democrats. I have, therefore, coded Maine as light purple.

As we all know, the red, blue, and purple maps are limited in what they tell us. And, in the case of the Senate, this is particularly true. Each state has two senators—and only two—who represent the entire state. Elected by popular, statewide vote, these senators can represent widely divergent numbers of people. For example, the state of California has over 39.5 million residents. That’s one senator for every 19.8 million people (keeping in mind that each senator represents the entire population of 39.5 million people). In Wyoming, on the other hand, the state population is less than 600 thousand people. That’s one senator for every 289 thousand people.

In terms Proportional power, this means that a person in Wyoming has 68 times more influence in the U.S. Senate than a person in California.

In the visualization below, I demonstrate senatorial representation in each state by dividing the population by their two senators—i.e. the number of senators per person in each state. The higher the resulting number, the less proportionate power residents of that state have. California, New York, Texas, and Florida stand out as being the most disproportionally underrepresented states by population in the Senate.

I’ve also grouped the states party affiliation of their senators. The average Democratic state has one senator for every 3 million people. The average Republican state has one senator for every 1.8 million people. In other words, Republican states have roughly 1.6 times more proportional power than Democratic states. Purple states lean closer to the average of Democratic states with one senator for every 2.9 million people.

Maine and Vermont, each with an independent senator that caucuses with the Democrats could be grouped with the blue states, which creates a cleaner visualization, but doesn’t significantly affect the numbers.

The current system in the Senate clearly favors residents of Republican states.

The numbers above hide the way in which disproportionate representation in the U.S. Senate gives disproportionate power to white populations. By way of example, let’s return to California and Wyoming. California has 39,512,223 residents while Wyoming has 578,759 residents. In Wyoming, 83.7% of the population is white, 10.1% of the population is Hispanic or Latino, 2.7% are Indigenous Americans, 1.3% are Black, and 1.1% are Asian. In California, 36.5% of the population is white, 39.4% of the population is Hispanic or Latino, 1.6% are Indigenous Americans, and 6.5% are Black, 15.5% are Asian. As demonstrated above, residents in Wyoming have 68 times more proportional power than residents of California. Looking at population breakdowns, these numbers demonstrate that white population of Wyoming have disproportionate power in the U.S. Senate vis-à-vis people of color in California. We could do this exercise with any number of states (and perhaps I’ll put together a visualization in the future), but overall, the numbers demonstrate that the U.S. Senate of the 116th Congress gave outsized power to white residents of Republican states.

But, of course, there is another part of this story—the territories of the United States, which include Washington D.C., Puerto Rico, Guam, American Samoa, the Northern Mariana Islands, and the U.S. Virgin Islands. These territories have a combined population of over 4.2 million people—significantly more than the populations of Wyoming, Vermont, Alaska, South Dakota, and Montana combined and slightly more than the population of Oregon. These 4.2 million residents in territories claimed by the United States have not a single senator that represents them.