On January 17, four states sued the federal government to force the Census Bureau to ask about the immigration status of each person. The State of Louisiana v U.S. Department of Commerce, w.d. Louisiana, 6:25cv-76. The other states in the lawsuit are West Virginia, Ohio, and Kansas. Here is the Complaint.
The suit claims that if the population figures for each state reflected the number of illegal aliens, and those persons were not included in the formula for determining the number of U.S. House seats, that states like Louisiana and West Virginia would gain another member of the U.S. House, and of course certain other states, like California and Texas, would lose some seats.
The reason the Census Bureau doesn’t ask about immigration status is that if the question were asked, many people would refuse to cooperate with the Census.
The Fourteenth Amendment, Section Two, covers apportionment of U.S. House seats. It says, “Representatives shall be apportioned among the several States according to their respective numbers, counting the whole number of persons in each State, excluding Indians not taxed.”
The case has not yet been assigned to any particular judge.