(CNN) - The US Supreme Court said on Friday that it will take up a case related to the decision to include a question about citizenship on the next census.
The justices will review whether challengers can introduce evidence outside of the official record, beyond what the government based its decision on, including the testimony of a senior Justice Department official.
A key issue in the case is whether challengers can depose Commerce Secretary Wilbur Ross, who has jurisdiction over the census.
The court last month temporarily blocked Ross from having to face a deposition on the issue, which was seen as a partial win for the Trump administration.
The administration argued that such a deposition of a Cabinet official is "rarely, if ever justified." However, at the time the court allowed the deposition of acting Assistant Attorney General John M. Gore of the Civil Rights Division, as well as other discovery, to proceed.
Oral arguments before the Supreme Court are set for February. The timing is unusual because a lower court is still considering the case in New York.
Challengers in the case include a coalition of states and the American Civil Liberties Union. They want to press Ross on his rationale for adding the question, as they believe it was included to reduce the representation of immigrant populations.
The Justice Department declined to comment to CNN on Friday.
Dale Ho, director of the ACLU's Voting Rights Project, said in a statement that "all relevant evidence should be considered."
"The Trump administration is terrified of having to explain on the record why it added a census citizenship question, and has repeatedly tried to shield Commerce Secretary Wilbur Ross from answering questions under oath. All relevant evidence should be considered," Ho's statement said in part.
Former Attorney General Jeff Sessions last month condemned efforts to depose Ross. However, days after the administration filed its request with the court last month to block the deposition, new questions arose about previous comments Ross had made to Congress about the controversial census question.
An October Justice Department filing revealed that Steve Bannon had contacted Ross in the spring of 2017 -- when Bannon was a senior Trump adviser -- asking him to speak with Kansas Secretary of State Kris Kobach about including a citizenship question.
Ross had denied to Congress last March that anyone from the White House had discussed adding that type of question to the census with him, adding days later that it was an initiative from the Justice Department.
CNN previously reported that a Commerce Department spokesman, speaking on the condition of anonymity, said Ross' comments before Congress were not misleading.
The spokesman said the Justice Department "response supplements the record but does not change the secretary's story, it only adds to it."
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