A privacy watchdog group has asked a federal judge to block the Trump administration from adding a citizenship question to the 2020 census questionnaire.

The Census Bureau didn’t consider the impact of collecting personal information about citizenship status on individuals’ privacy rights, the Electronic Privacy Information Center alleged in a Nov. 20 lawsuit.

The Department of Commerce, which oversees the Census Bureau, “failed to conduct a legally sufficient—or in some cases, any—Privacy Impact Assessment for the collection, processing, and...