John H. Thompson, the director of the U.S. Census Bureau, just resigned amid a funding fight over the 2020 Census.

Since it comes at the same time that the president fired the director of the FBI, why should anyone care about the resignation of just another Washington “bean counter”?

This bean counter, whose name is likely unfamiliar to the vast majority of Americans, is actually one of the most important people in determining whether Democrats or Republicans control Congress. The census has a significant impact on political representation and how federal money is distributed. Moreover, how hard the director fights for more funding helps determine the accuracy of the census.

As someone who has spent decades deeply involved in surveys, I understand the importance of ensuring an accurate count of the population. Without it, every fact about this nation’s population – from the percent of women giving birth to the percent of elderly people dying – is suspect.

Why we have a census

The primary source of United States demographic data is the population census, which is done in the spring of all years that are evenly divisible by 10.

The U.S. Constitution provides the legal basis for conducting a census in Article 1, Section 2, Clause 3, later superseded by the 14th Amendment:

“Representatives shall be apportioned among the several States according to their respective numbers, counting the whole number of persons in each State, excluding Indians not taxed.”

The first census was conducted in 1790, a year after the inauguration of President George Washington. The law establishing it required that marshals visit every household and send the “aggregate amount of each description of persons” for every district to the president. The data were to be used to distribute seats fairly in the House.

Today, the census’ goal more broadly is to collect information about all people residing in the country, including noncitizens.

But it’s used for many purposes beyond a state’s congressional representation. It determines how the federal government distributes billions of dollars in aid. It also controls the number of Electoral College votes each state receives. This means the census has a big part to play in who is elected president in close elections.

At the state and local level, the census is used for zoning, planning and situating public services. The census is even important for businesses, since it provides the raw data needed for planning, marketing, production and distribution decisions.

How the census works

The census does all these things by trying to track down every single person in the country and tally how many live in the U.S. on April 1 of the year in question.

The bureau maintains the country’s most accurate and complete mailing list, called the Master Address File. This file contains records for every single home, apartment, dormitory and other type of residence in the country. But, while this count of residences is very accurate, it doesn’t tell the Census Bureau who lives where.

To find out, the bureau sends a detailed form to every address on its list. It asks residents to fill it in and mail it back. This is where most of the census results come from.

If a form isn’t returned, the Census Bureau attempts to reach the occupants of an address through telephone calls and face-to-face visits. That task has become more complicated, as more Americans have switched from landlines – which are tied to a physical address – to unattached mobile phones. This has increased the cost of tracking down people who don’t fill out the forms.

Additionally, in large urban areas, census staff and homeless advocates tally the number of individuals living on the streets. Census staff even go to mobile home parks, campgrounds and boat marinas to ensure that people who are traveling are included in the tally. With help from the military, the census also counts U.S. citizens stationed overseas or on active duty ships.

Tallying the costs

The census goes to extraordinary lengths, particularly in more recent surveys, to provide a complete picture of the entire population – not just those who are conveniently reachable. This extraordinary effort costs money.

Census costs have soared over time, a problem made worse as more Americans have stopped answering surveys and toss spam-like mail into the trash without opening it. In the last census, in 2010, 74 percent of Americans mailed back a completed form.

In 1970, the census cost about US$1.3 billion, after adjusting for inflation. That figure tripled to $12.5 billion in the 2010 census. This massive undertaking – which involved more than 600,000 temporary workers – put the U.S. population at 308,745,538.

Congress wants the 2020 Census to cost no more than the last one. Yet the bureau estimated in 2011 that it would likely cost $22 billion to $30 billion. Even just factoring in inflation means spending at least $15 billion for the 2020 census.

The funding dispute that may have led to Thompson’s resignation was over the extra money needed ahead of the census. Congress agreed to give the Census Bureau $1.47 billion for fiscal year 2017, 10 percent less than President Barack Obama’s request. The current White House proposal is just $1.5 billion for 2018, far less than what is needed, according to critics.

In addition, the bureau is over budget by 50 percent in its effort to transition to a new electronic data collection system, which if fully funded could eventually lead to less costly yet still accurate censuses.

Why it matters

Census funding has a direct link to how much political power more marginalized members of society have.

Since congressional seats in the House are distributed by population, our country’s intense political polarization means small differences in representation can matter quite a bit.

A census done quickly and on the cheap will tend to count easy-to-find people at the expense of those in the cracks. A very thorough census, on the other hand, picks up people who are undercounted in the first pass because they didn’t fill out their forms.

The size of the undercount has political implications. Kenneth Prewitt, director of Census Bureau during the 2000 count, cites a memo written in 1997 by the chairman of the Republican National Committee that states adjusting for the undercount “could provide Democrats the crucial edge needed to prevail in close contests.”

The official report of the last census said that blacks and Hispanics – who tend to favor Democrats – were undercounted by about 2 percent. As the report explained, this happens “because ethnic and racial minorities disproportionately live in hard-to-count circumstances.” Meanwhile, some whites were counted more than once.

Yet this was a huge improvement over 1990, when 4.4 percent of blacks were undercounted. In other words, all that extra money the government poured into the 2000 and 2010 censuses paid off in more accuracy.

What can you do?

So why does it matter who the director is? Thompson, who became director in 2013 and had been with the bureau for more than 30 years, was pushing for more funding to do a better census.

With Congress and the White House currently focused on slashing budgets, I believe the chances are high that the president will appoint and Republican senators will confirm a replacement who is happy to spend less money on a census that undercounts people who will likely vote for their political foes.

There’s something simple you can do to make sure you’re represented – which, as a matter of fact, will save the government money as well. In less than three years, the Census Bureau will begin sending out its forms in the hopes of reaching every person residing in the U.S. You can reduce government costs and ensure you have appropriate representation in Congress by simply filling out and returning the form promptly, and helping others to do the same.

As the Founding Fathers understood, the basis of democracy is fair representation. An accurate census ensures we stay true to that original goal.

Jay L. Zagorsky does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.