What would an inaccurate census mean for the United States?

Getting an accurate count of all Americans for the census every 10 years is an enormous task under any circumstances. In 2020 it may prove to be impossible. The combined challenges of the coronavirus pandemic and policy changes by the Trump administration have some experts worried that this year’s census may be the least accurate count in modern history.

In a normal year, census data collection starts in January and is completed by the end of July. The Census Bureau then has until Dec. 31 to process the data and...