Citizenship and the census: What’s at stake in Supreme Court case

“Is this person a citizen of the United States?”

That is the question at the heart of several others the U.S. Supreme Court asked Tuesday in a case concerning whether it is lawful for the Department of Commerce to include a question on citizenship in the 2020 census.

In an expanded 80-minute-long argument, the justices probed a technically complex and detailed case that could have broad and long-reaching consequences for millions of people around the country. While the core issues in the case concern the next census specifically, and the...