A second federal judge has issued a court order to block the Trump administration's plans to include a citizenship question on the 2020 census.
U.S. District Judge Richard Seeborg of California found that the administration's decision to add the question violated administrative law.
The judge also ruled that it was unconstitutional because it prevents the government from carrying out its mandate to count every person living in the U.S. every 10 years.
"In short, the inclusion of the citizenship question on the 2020 Census threatens the very foundation of our democratic system — and does so based on a self-defeating rationale," Seeborg wrote in a 126-page opinion released Wednesday.
Plans to add the question have already been halted by an earlier ruling in New York by U.S. District Judge Jesse Furman.
The Supreme Court is scheduled to hold a hearing about the New York ruling on April 23. This latest ruling will likely be appealed to the high court.
The controversial question asks, "Is this person a citizen of the United States?"
The administration argues that the Justice Department wants responses to the question to better enforce Voting Rights Act provisions that protect racial and language minorities against discrimination. In his ruling against including the question, however, Furman found that to be a "sham justification."
Census Bureau officials have recommended against adding the question, which the federal agency's research suggests will scare noncitizens and some citizens from participating in the constitutionally mandated head count of every person living in the United States.
The dozens of states, cities and other groups that have sued the administration over the question are concerned that it will lead to an undercount of Latinos and other communities of color. That would harm the accuracy of new population counts that play a role in determining how many congressional seats and Electoral College votes, as well as how much federal funding, each state receives after the 2020 census.