The Enumeration Clause

The actual Enumeration shall be made within three Years after the first Meeting of the Congress of the United States, and within every subsequent Term of ten Years, in such Manner as they shall by Law direct.

—Andrew C. Spiropoulos

Introduction

Under the Constitution, representation in the House of Representatives is based on population. The Enumeration Clause requires that an “actual Enumeration” be taken every decade. There are two possible bases for the enumeration: The actual enumeration would rely on the physical count of people, while an estimated enumeration would supplement the physical count with estimating or sampling methods. The legitimacy of measuring population with estimating methods was a subject of serious debate in England and its American colonies.

Although delegates to the Constitutional Convention did not discuss this question directly, revisions of the draft language by the Committee of Style support the actual enumeration position. The first census in 1790 relied only on the actual count and did not employ estimates, but doubts nevertheless emerged about inaccurate population counts, and these doubts had important political and policy consequences. Over time, expert statisticians argued that estimating or sampling methods would yield more accurate results. In 2002, the Supreme Court held that the Constitution permits the use of a sampling methodology and does not confine the government to its actual count.

English and Colonial Practice

In the eighteenth century, the distinction between actual counting and estimating was well known and thoroughly discussed in controversies between the American colonies and England.¹ For example, in 1769, Richard Price, a writer known for his expertise on actuarial matters, applied estimating methods to show that the population in England and Wales had declined.² Critics excoriated him for relying on conjecture instead of actual evidence.³ They insisted that the only way to count the population was to conduct an actual enumeration.⁴ This phrase was crafted directly in response to the call for the use of estimates. The debate culminated in the passage of the Census Act of 1800, which rejected the use of estimates in favor of a full and actual enumeration.⁵

The Constitutional Convention

During the Constitutional Convention, there was no direct discussion regarding whether apportionment would be based on an actual count or on estimates. The Committee of Detail’s draft of the section stated that the number of inhabitants “shall . . . be taken in such manner as . . . [Congress] shall direct.”⁶ Then, echoing the language used by Price’s critics, the Committee of Style added “actual Enumeration.”⁷

Gouverneur Morris of Pennsylvania served on the Committee of Style. There is an emerging scholarly debate about whether, contrary to the stylistic charge of the Committee, Morris used his position to alter the substance of the Constitution. Professor William Michael Treanor, for example, has observed that the “‘actual enumeration’ language advanced the same underlying goals at the core of [Morris’s] constitutional vision: limiting the power of new states and weakening the slave states.”⁸ Morris thus favored the actual count arguably required by the revised language rather than estimates.

The Convention also rejected a proposal that apportionment should be based on wealth and population. Several delegates argued that a rule based on population alone would provide a more certain basis for apportionment because a wealth rule would necessitate the use of estimates.⁹

The Ratification Debates

During the ratification debates, critics warned that through political chicanery, the taxing power could be used to discriminate against particular states. In Federalist No. 36, Alexander Hamilton reassured his audience that the population figures for taxes would be based on an actual enumeration that was not subject to political manipulation. He wrote that “an actual census or enumeration of the people must furnish the rule, a circumstance which effectually shuts the door to partiality or oppression.”

Early Practice

Following ratification, the Census Act of 1790 established the first census. The law required an actual counting. Census takers were required to swear an oath that they would “truly cause to be made, a just and perfect enumeration and description of all persons resident within [their] districts.”¹⁰

Under the original design of the Constitution, the census counted the number of “free Persons” as well as the number of “other Persons.” This latter number referred to slaves, three-fifths of whom would be included in the number used to apportion representatives. The Thirteenth and Fourteenth Amendments superseded the Three-Fifths Clause, ensuring that representation is now based on the “whole number of persons” in each state.

Judicial Precedent

In 1996, the U.S. Supreme Court declared that the text of the Enumeration Clause “vests Congress with virtually unlimited discretion in conducting the decennial ‘actual Enumeration’” and that Congress “has delegated its broad authority over the census to the Secretary [of Commerce].”¹¹ In the Census Act of 1954, as amended in 1974, Congress had delegated to the Secretary of Commerce the broad authority to conduct the census “in such form and content as he may determine, including the use of sampling and special surveys.”¹²

Then, in 1999, U.S. Department of Commerce v. U.S. House of Representatives held that the Census Act prohibited the use of statistical sampling to calculate population numbers.¹³ However, the majority did not reach the constitutional question. Justice Antonin Scalia wrote a concurrence in which he found that statistical sampling violated the Enumeration Clause and that the words “actual Enumeration” mean “counting ‘singly,’ ‘separately,’ ‘number by number,’ ‘distinctly.’”¹⁴ In dissent, Justice John Paul Stevens found that the use of statistical sampling was consistent with the phrase “actual Enumeration.”

Three years later, the Court held in Utah v. Evans (2002) that an inferential counting methodology did not violate the Enumeration Clause.¹⁵ Writing for the majority, Justice Stephen Breyer concluded that the Framers “did not write detailed census methodology into the Constitution.”¹⁶ Therefore, the inferential method used in this case, which did not involve actual counting, was constitutionally valid. Justice Clarence Thomas dissented. He observed that the Framers, “[w]ell familiar with methods of estimation . . . chose to make an ‘actual Enumeration’ part of our constitutional structure” but that “[t]oday, the Court undermines their decision, leaving the basis of our representative government vulnerable to political manipulation.”¹⁷

In Department of Commerce v. New York (2019), the Supreme Court opined that the Enumeration Clause permits the federal government “to use the census for more than simply counting the population.”¹⁸ This power includes the ability to inquire about citizenship on the census questionnaire. The Court, however, ultimately held that the decision by the Secretary of Commerce to inquire about citizenship must be set aside because he offered a pretextual rationale for the decision.

Open Questions

• Utah v. Evans upheld a relatively narrow sampling methodology. The 2020 census, by contrast, relied on broader sampling methodologies.¹⁹ Such approaches have not been tested in the courts. A future case may consider whether other forms of sampling violate the Enumeration Clause.
• In Department of Commerce v. New York, Justice Breyer’s dissent favorably cited Justice Thomas’s dissent in Utah v. Evans. Breyer warned that counting methods employed must limit “political chicanery” and prevent the census from being “skewed for political purposes.”²⁰ What sorts of methodologies may cross this line?
• Does the government exceed its authority under the Enumeration Clause when it employs the census to seek other demographic information, including race and family relationships?²¹

1. Thomas R. Lee, The Original Understanding of Census Clause: Statistical Estimates and the Constitutional Requirement of An “Actual Enumeration”, 77 Wash L. Rev. 1, 39–47 (2002). ↩︎
2. Id. at 26–27. ↩︎
3. Id. at 28–32. ↩︎
4. Id. at 34–39. ↩︎
5. Id. at 21–41. ↩︎
6. 2 Farrand’s 182–83, 571–72. ↩︎
7. Id. at 590–91. ↩︎
8. William Michael Treanor, The Case of the Dishonest Scrivener: Gouverneur Morris and the Creation of the Federalist Constitution, 120 Mich. L. Rev. 1, 71 (2021). ↩︎
9. 1 Farrand’s 582. ↩︎
10. 1 Stat. 101. ↩︎
11. Wisconsin v. City of New York, 517 U.S. 1, 19 (1996). ↩︎
12. 13 U.S.C. § 141(a). ↩︎
13. 525 U.S. 316 (1999). ↩︎
14. Id. at 347. ↩︎
15. 536 U.S. 452 (2002). ↩︎
16. Id. at 479. ↩︎
17. Id. at 510. ↩︎
18. Dept. of Comm. v. New York, 588 U.S. 752, 769–70 (2019). ↩︎
19. American Statistical Association, 2020 Census State Population Totals: A Report from the American Statistical Association Task Force on 2020 Census Quality Indicators (Sept. 2021), https://perma.cc/UF6W-AK25. ↩︎
20. Dept. of Comm. v. New York, 588 U.S. at 803. ↩︎
21. Stephen Kruger, The Decennial Census (Apr. 6, 2025), https://ssrn.com/abstract=1985554. ↩︎