A Citizenship Question on the US Census

The Trump administration is facing a legal challenge to its efforts to add a citizenship question to the 2020 decennial census—a question that was first included in 1890, but has not been asked of the entire population since 1950. If the citizenship question was asked in the past, why not reinstate it? Senior Scholar Joel Perlmann explains how the characteristics of both immigration and the census itself have changed radically since 1890 and, as a result, how the inclusion of this question on the once-a-decade census would not only be redundant, but would threaten the integrity of the census count.