Brennan Center Research Shows No Historical Justification for a Census Citizenship Question

April 3, 2019

In an article published by the Georgetown Law Journal, Brennan researchers show that the Trump Administration’s historical defense of the 2020 Census citizenship question is wrong .

MEDIA CONTACT: Mireya Navarro;; 646 925 8760 

Just as the U.S. Supreme Court is set to hear oral arguments on the Trump Administration’s efforts to add a new, untested citizenship question to the 2020 Census form, the Georgetown Law Journal has published Brennan Center research that shows such a question would be unprecedented and contrary to what the Census Bureau considers best practices for an accurate count.

In “A Critical History of the United States Census and Citizenship Questions,” authors Thomas P. Wolf and Brianna Cea write that Commerce Secretary Wilbur Ross has defended his decision to include the question with “misleading” and “demonstrably false” claims. In particular, he maintains that most census counts in our history have asked about citizenship and that placing the question on the census is consistent with a “traditional status quo.”

In research going back to 1820 (please see page 34 for a decade-by-decade comparison chart in article), the authors found that citizenship questions have appeared only sporadically and have been asked only of a subset of people, when they have been asked at all. These questions have their origins in a whole approach to census-taking that the Bureau decades ago conclusively rejected to obtain a more accurate national head count.

Wolf, counsel with Brennan’s Democracy Program, and Cea, a research and program associate in the program, further note that after the advent of statistical sampling, which vastly improved the head count, the Census Bureau removed citizenship questions for good from the questionnaire used to obtain the complete population count, using it only in the longer form that currently goes to a fraction of people.

“A broader view of census history – one that includes not just the what and when, but also the why and how of the decennial count – shows that citizenship questions are not compatible with the full enumeration that the Constitution requires,” the authors write.

Among the Journal article’s highlights:

* Citizenship questions appeared only sporadically between 1820 and 1950. They were asked only of subsets of people for purposes such as tracing the assimilation of foreign-born people or ensuring that emancipated people obtained their full civil rights after the Fourteenth Amendment was ratified.

* Early citizenship questions reflected an older model of census-taking that the Census Bureau discarded once it gained the technical ability to understand how systemically flawed and inaccurate that model was.

* After the 1950 census, the Census Bureau removed the citizenship question from the questionnaire used to obtain the complete population count and transferred it to sample surveys, where it remains.

*Citizenship questions have become increasingly associated with exclusionary politics that threaten to depress the count.

The Brennan Center for Justice at NYU Law has filed a friend-of-the-court brief in the Supreme Court case to be heard April 23. It argues that the government’s addition of a citizenship question threatens to undermine both the enforcement of voting rights, the purported reason for adding the question, and the response rate, skewing the allocation of congressional seats and billions of dollars in federal funding to states.

The Brennan Center’s amicus brief:

 The Brennan Center’s 2020 Census Page:


The Brennan Center for Justice at NYU School of Law is a nonpartisan law and policy institute that works to reform, revitalize — and when necessary, defend — our country's systems of democracy and justice.