The government announced Monday night it will include citizenship questions on the 2020 U.S. census, prompting a federal lawsuit that evening from California and threats of other suits by more states.

The U.S. Department of Commerce said the inclusion of citizenship status on the census questionnaire came at the request of the Department of Justice to assist with enforcement of the Voting Rights Act.

“Citizenship questions have been included on prior decennial censuses,” the Commerce Department said. “Between 1820 and 1950, almost every decennial census asked a question on citizenship in some form.”

Critics of the move say it could lead to inaccurate counts, in violation of the constitutional requirement that the census takes “actual enumeration” of every person in every state, every 10 years.

“It is long settled that all persons residing in the United States — citizens and non-citizens alike — must be counted to fulfill the Constitution’s ‘actual Enumeration’ mandate,” the lawsuit says.

While California Attorney General Xavier Becerra alleges violations of the Administrative Procedure Act, New York Attorney General Schneiderman vowed Tuesday to bring his own multistate suit over the proposed census changes.

“The Trump administration’s reckless decision to suddenly abandon nearly 70 years of practice by demanding to know the citizenship status of each resident counted … will create an environment of fear and distrust in immigrant communities that would make impossible both an accurate census and the fair distribution of federal tax dollars,” Schneiderman said in a statement.

Last month, Schneiderman and Becerra led 20 states in a letter that protested an early step the Commerce Department had taken toward adding the citizenship question to the census.

Commerce Department Secretary Wilbur Ross said the principle reason for including citizenship questions is to enforce the Voting Rights Act, citing a request from the DOJ.

“DOJ seeks to obtain citizen voting age population data for census blocks, block groups, counties, towns, and other locations where potential Section 2 violations are alleged or suspected,” Ross said in a Monday letter.

Ari Berman who covers voting rights at Mother Jones calling this rationale a farce.

“Trump DOJ hasn’t filed single lawsuit to enforce Voting Rights Act,” tweeted Berman.

Instead, the DOJ has taken a position supportive of many of the restrictive voter ID laws that have been struck down by courts, such as a recent one in Texas, he said.

President Donald Trump’s re-election campaign touched on the issue in an email last week, asking people whether or not they are citizens of the country is “common sense.”

The email said:

“The President wants the 2020 United States Census to ask people whether or not they are citizens. In another era, this would be COMMON SENSE… but 19 attorneys general said they will fight the President if he dares to ask people if they are citizens. The President wants to know if you’re on his side.”

Ross said the obligation to get complete and accurate census data outweighed any adverse impacts which his department determined to be minimal.

The American Civil Liberties Union is fighting the change as well, noting that the census is a determinative force in deciding how many congressional seats each state is allocated and to a degree how they are drawn on the map.

“Undercounting communities with large immigrant populations could mean weakened political representation, and the loss of millions in aid for health, education, and infrastructure,” the ACLU said in a statement Monday.

California Attorney General Becerra and California Secretary of State Alex Padilla will hold a press conference Tuesday afternoon on their lawsuit.