GREENBELT, Md. (AP) - A federal judge in Maryland is hearing testimony for a trial involving the Trump administration's addition of a citizenship question to the 2020 census. The plan has already been blocked by a different judge.

Former U.S. Census Bureau director John Thompson was the first plaintiffs' witness for the bench trial that started Tuesday before U.S. District Judge George Hazel in Greenbelt, Maryland. Plaintiffs include residents of Arizona, Florida, Nevada and Texas.

The trial began a week after a federal judge in New York ruled Commerce Secretary Wilbur Ross acted in an "arbitrary and capricious" manner before deciding to add the citizenship question. The Justice Department is appealing that ruling.

A trial began earlier this month in San Francisco for a separate lawsuit over the same issue, filed by the state of California.

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