The U.S. Conference of Mayors is joining the legal action as well.
Attorneys general from 17 states and the District of Columbia, along with six cities and a bipartisan group of mayors, filed a lawsuit Tuesday in an effort to block the Trump administration from including a controversial question about citizenship in the 2020 census.
The Commerce Department announced last month that, following a request from the Department of Justice, the Census Bureau plans to ask everyone surveyed during the next decennial population count about their citizenship status. DOJ asked for such a question to be included to help enforce the Voting Rights Act, according to Commerce.
The lawsuit, which names the Commerce Department and the Census Bureau as defendants, contends the question would "fatally undermine the accuracy" of the census.
And it notes that the Constitution requires the federal government to conduct an "actual enumeration" of the population every 10 years to determine the "whole number of persons" in the U.S.
"With immigrant communities already living in fear, demanding citizenship status would drive them into the shadows, leading to a major undercount," New York Attorney General Eric Schneiderman, who is leading the suit, said in a statement on Tuesday.
The census helps to guide the distribution of billions of dollars in federal funding, as well as the allocation of congressional representatives for each state and members of the Electoral College.
Asking about citizenship status on the census, the lawsuit argues, threatens to deter participation in immigrant communities because of concerns about how the federal government will use the information. This raises the prospect that states with large immigrant populations could see federal funds or political representation eroded due to undercounting.
Contrary to the Justice Department's stance, Schneiderman and others have said including a citizenship question on the census would actually run counter to the goals of the Voting Rights Act, which seeks to protect against discrimination of minorities at the polls.
California Attorney General Xavier Becerra filed a lawsuit last week challenging the question. The Golden State, with its sizable immigrant population, is among those with the most to lose if the question leads to the sort of undercounting some critics are warning about.
Citizenship questions consistently appeared on decennial census forms distributed by the government until 1950, according to a March 26 memo from Commerce Secretary Wilbur Ross.
The memo adds that a citizenship question was included on forms distributed to one in six people in 2000, and that since 2005 one has appeared as part of the American Community Survey—a yearly survey that is narrower in scope than the full census.
Joining the attorneys general and cities that filed Tuesday's lawsuit is the U.S. Conference of Mayors.
“Mayors of both parties have long contested that previous censuses have undercounted cities, limiting the federal resources that their communities deserve," executive director Tom Cochran said in a statement. "The U.S. Conference of Mayors stands united in opposing the addition of the citizenship status question to the 2020 Census."
The attorneys general joining Schneiderman in the suit hail from Connecticut, Delaware, Illinois, Iowa, Maryland, Massachusetts, Minnesota, New Jersey, New Mexico, North Carolina, Oregon, Pennsylvania, Rhode Island, Virginia, Vermont, Washington and the District of Columbia. New York City, Chicago, Philadelphia, Providence, San Francisco, and Seattle are the cities that have signed on.
The lawsuit was filed in the U.S. District Court for the Southern District of New York.
It was brought under the Enumeration Clause of the Constitution, as well as the Administrative Procedure Act, which allows courts to set aside agency decisions deemed to be unlawful, arbitrary or capricious.
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