A federal judge in Maryland on Wednesday allowed [memorandum, PDF] a lawsuit filed by residents of both Maryland and Arizona over the census citizenship question to proceed.

The lawsuit arises out of an additional question to the 2020 census questionnaire that asks citizens “whether each household member is a citizen of the United States by birth or naturalization, or not a U.S. citizen.” The judge is allowing the suit to go forward and letting the plaintiffs argue in court.

The plaintiffs are alleging that the “justification for adding the citizenship question is a pretext for its true aim – ‘to press the 2020 Census into the service of [President Trump’s] anti-immigration political agenda.'” They are also alleging that there is no government benefit of adding this citizenship question, and in fact, argue the opposite. They argue that “the inclusion of a citizenship question will result in a disproportionate undercount of persons belonging to or sharing a household with certain demographic groups, including immigrants, noncitizens, those with limited English proficiency, and individuals of Hispanic or Latino Origin.”