President Donald Trump was sued over this week's executive order that seeks to exclude undocumented immigrants from being included in census data used to divide up seats in Congress.
Trump signed the order Tuesday that proclaimed that it's "the policy of the United States to exclude from the apportionment base aliens who are not in a lawful immigration status."
Legal scholars predicted quick legal challenges to the policy.
The nonprofit activist group Common Cause was the first to the punch, filing a complaint late Thursday in federal court in Washington.
The policy "flouts the Constitution's plain language, which states that '(r)epresentatives shall be apportioned among the several states according to their respective numbers, counting the whole number of persons in each state,'" according to the complaint.