The Constitution calls for an “actual Enumeration” of each state’s population every 10 years, and since 1790, Congress has enacted legislation to fulfill that mandate. The decennial count, managed at the United States Census Bureau, aims to fulfill that constitutional requirement.

Next week , in what promises to be the highest-profile case of this Supreme Court term, the court will consider whether the Trump administration complied with these dictates when it sought to add to the 2020 census a question about whether the respondent is a United States citizen.

At the heart of the dispute lies the question: Who gets to be counted?

Federal law protects the privacy of everyone who responds to the census. But that’s small comfort for immigrants and their families living in a climate of fear under President Trump. Bureau officials have for decades recognized that communities with significant immigrant populations are likely to be undercounted if there is a citizenship question on the census.

The 2020 count is no exception. Three federal judges — in New York, California and Maryland — have held trials and ruled that Wilbur Ross, the commerce secretary, who oversees the Census bureau, violated the law when he ignored available data and ordered the agency to move ahead with the citizenship question.