A Case for Doubling the Size of the US House of Representatives

The House of Representatives is too small. It has had at or around 435 members since 1913. At that time, each representative had an average of 210,583 constituents. Since then, the number of constituents per representative has increased to 761,169. In other words, each individual constituent’s representation in congress has been diluted by almost a factor of four (figure 1).

To put it simply: the U.S. population has grown a lot in the past century, and the House of Representatives has not. Consequently, each person has less representation in congress. States have unequal representation in congress and unequal voting power in the electoral college because it is impossible to equitably apportion 435 seats among states with different populations. These issues will worsen over time unless the House of Representatives is expanded.

In this article, we detail the ways in which the fixed size of the House has diluted congressional representation and caused unequal representation of states. We show that increasing the size of the House is a powerful way to mitigate these issues and review several existing proposals. We show that these proposals are inadequate, and introduce our own: that the size of the House be at least doubled to 870 members, and that the size of the House increase over time with the U.S. population.

The Size of the U.S. House of Representatives Affects Your Representation in Congress and Your Vote in Presidential Elections

Why does it matter how many constituents each House seat represents? First, as the U.S. population increases and the size of the House of Representatives remains the same, each individual’s representation in Congress is diluted. Second, because the size of the House is fixed at 435 members (the permanent apportionment act of 1929 set this number into law), there will necessarily be significant inequalities in representation between states. Finally, states receive one electoral vote for each member of the House, so unequal representation in Congress translates to unequal voting power between states.

Population Growth Dilutes Congressional Representation

Members of the House of Representatives are supposed to represent the best interests of the people living in their congressional districts. Representatives responsible for more than 760,000 constituents each can’t be adequately responsive to the needs of their constituents. As the population grows, it becomes more difficult for representatives to keep track of the local conditions and specific needs of their growing constituencies.

As shown in figure 1, the ratio of constituents to representatives has increased over time as the population has grown and the number of representatives has remained the same. This trend holds true in every state: even the most overrepresented states today have higher constituent-to-representative ratios than the most underrepresented states in 1960.

States are Represented Unequally in the House of Representatives

Dilution of representation is not the only problem. In a prior post on the topic of congressional apportionment, we discussed how the present apportionment method results in inequalities in representation between states.

In 1910, the single representative from the most overrepresented state, Nevada, represented 81,875 people, compared to 228,027 constituents each for five representatives in the most underrepresented state (Washington): a difference of 146,152. After the reapportionment following the 2020 census, the difference between the most underrepresented state (Delaware) and the most overrepresented state (Montana) will increase to 448,133 constituents. In other words, the representative from Delaware will be responsible for almost 450 thousand more constituents than either of the representatives from Montana: a much harder job. Put differently, each Delaware resident will be competing for their needs to be represented in congress against almost 450 thousand more people than each Montana resident.

This unequal representation is not a new problem. Figure 2 shows that, despite some fluctuation over time, there has always been a significant gap between the most under- and overrepresented states. For most of the last century, they have deviated from the ideal representative to population ratio by more than 20 percent (and sometimes far more). We define this “ideal” ratio as the total U.S. population at each decennial census divided by the total number of representatives.

The degree of over- and under-representation can fluctuate over time. For example, following the 2010 census, Montana was actually the most underrepresented state in the House of Representatives: Montana’s one representative had more than 994 thousand constituents. Montana will gain an additional representative in 2023, following the midterm elections, making it the most overrepresented state. One could argue that a decade of overrepresentation will balance out a decade of underrepresentation. But wouldn’t it be better to have a system without such drastic fluctuations, where everyone could count on similar representation in congress?

Unequal Congressional Representation Results in Unequal Voting Power

Unequal representation also affects voting power as each state receives the same number of electoral votes as the size of its congressional delegation. Voters in states with high population-to-representative ratios, then, have less-valuable votes in presidential elections. Opportunities to correct these inequalities are rare as representatives—and therefore electoral votes—are only reapportioned every ten years.

Unequal representation in the House of Representatives, then, is doubly harmful to democracy. Individuals in underrepresented states have less input in legislative affairs and are less empowered to change the country’s course through presidential elections.

The House of Representatives Should Be Much Bigger

How can we fix all of this? Our previous post discussed ways that 435 representatives could be apportioned more fairly. But given the requirement that each state have at least one representative, there is no truly equitable way to apportion 435 representatives among 50 states with large differences in populations. But what about 500 representatives? 700? 1000?

Proposals for Increasing the Size of the House of Representatives

Increasing the size of the House of Representatives means that individuals, on average, have more representation in congress and that states tend to receive more equal representation. Determining the ideal size of the House of Representatives, however, is no easy task.

Several different proposals have been put forth over the years, including:

• James Madison proposed a constitutional amendment capping the size of each congressional district at 50,000 members. This would require a House of Representatives with almost 6,700 seats.
• The “Wyoming Rule” states that each congressional district should have roughly the population of the smallest state (Wyoming). This would require 574 seats in the House of Representatives, an increase of 139 seats.
• The “Cube Root Rule” is based on the observation that, in many democracies, the size of national legislatures is roughly the cube root of the country’s population. Bringing the United States in line with the cube root rule would require increasing the House of Representatives to 692 members, an increase of 257 seats.

Figure 3 compares these three expansion proposals to the present number of House seats. It also shows the consequence of doubling the size of the House; this will be discussed in greater depth later. All of these proposals significantly reduce the state median population-to-representative ratio compared to the current 435 seats (Madison’s proposal far more than the other two). This translates to smaller congressional districts, more responsive and locally aware representatives, and greater potential for a range of ideological perspectives to be represented.

The Wyoming Rule and the Cube Root Rule, however, still leave large gaps in representation between states. The cube root rule, for instance, results in a difference in population-to-representative ratio of more than 275,000 constituents between Vermont, the most underrepresented state under that proposal, and Alaska, the most overrepresented state. Both of these states’ ratios differ from the “ideal” ratio (national population-to-representative ratio) by more than 20 percent.

Madison’s proposal, on the other hand, may be excessive. At the very least, organizing 6,700 representatives would be a significant logistical challenge. In the words of Madison himself (The Federalist Papers №55):

the number ought at most to be kept within a certain limit, in order to avoid the confusion and intemperance of a multitude. In all very numerous assemblies, of whatever character composed, passion never fails to wrest the sceptre from reason. Had every Athenian citizen been a Socrates, every Athenian assembly would still have been a mob.

How many representatives would be needed to reduce this gap, without going too far?

The House of Representatives Should Be Doubled (at Least)

We computed the apportionment of representatives among states using 2020 Census state population data for every possible number of seats from 435 to 3,000. We computed the population-to-representative ratio for each number of seats, in addition to the ratios for the most under- and over-represented states (figure 3). Increasing the number of seats improves overall representation and reduces the inequalities between states.

As the number of seats increases, the representative to population ratio decreases and the differences between the most over- and underrepresented states decrease. Still, this does not provide a clear criterion for picking a new number of Seats.

Neither the Wyoming Rule nor the Cube Root Rule significantly resolve the issue of inequality between states. As shown in figure 5, both result in some states with constituent-to-representative ratios deviating from the ideal by 20 percent or more. Indeed, even increasing the size of the house to 800 members does little to reduce the proportional gap in representation between the most extreme states.

We propose that the House of Representatives be at least doubled to 870 members.

Unlike the Wyoming rule and the Cube Root rule, doubling the size of the House of Representatives would mitigate much of the inequality in representation—and electoral college voting power—between states. And though 870 members would doubtless present a logistical challenge, it is still a much more modest proposal than Madison’s 1789 proposal, which would now require close to 6,700 seats.

To be clear: we propose that the house be at least doubled in size. There would be benefits to expanding it even further. Increasing the size of the House beyond 1,500 members would mean no state’s constituent-to-representative ratio is more than 20% higher or lower than the ideal. It would also bring the national population-to-representative ratio closer to where it was in 1929, when the size of the house was fixed at 435 members. Past 2,000 members, almost all states would be within 10% of the ideal.

Lastly, the best solution is not to pick a new, bigger number and to stick with it forever. The House should grow with the U.S. population. Both the Cube Root Rule and the Wyoming Rule, for instance, require regular updates to the size of the House. Doubling the number of members of the House of Representatives would account for the last century of population growth—but what about the next one?