Matt Barreto ,Chris Warshaw ,Matthew A. Baum ,Bryce J. Dietrich ,Rebecca Goldstein and Maya Sen in the Monkey Cage:

The Trump administration’s attempt to add a citizenship question to the 2020 Census reaches the Supreme Court on Tuesday. Thus far, three federal judges have ruled against the Trump administration, most recently in Maryland. The Supreme Court will consider not only whether the administration violated administrative law, but also whether its attempt violated the Constitution.

A crucial issue in the case is whether adding this question for the first time since 1950 will hurt the ability of the census to accurately count the American population. In particular, critics of the administration fear the question will dissuade some U.S. residents, especially immigrants, from answering the census.

Research suggests these fears are justified. Working separately, we have used surveys and experiments to show that the citizenship question would make people less likely to respond to the census and provide complete information if they do respond. This is particularly true for Latinos and immigrants.