Trump signs order targeting undocumented immigrants in the U.S. census

Washington (CNN)President Donald Trump signed a presidential memorandum on Tuesday that would exclude undocumented immigrants from being counted in congressional districts when district lines are redrawn next year.

The memorandum marks the Trump administration's latest effort to change the way US populations are counted and advance the President's immigration agenda, and like previous efforts is certain to end up in court.

"I have accordingly determined that respect for the law and protection of the integrity of the democratic process warrant the exclusion of illegal aliens from the apportionment base, to the extent feasible and to the maximum extent of the President's discretion under the law," the executive order states.

Trump has long sought to use the US census as a way to advance his immigration priorities but the Supreme Court rejected an attempt to ask respondents if they are US citizens in 2019. The administration, however, is allowed to collect information on citizenship status by other means.

And like the attempt to add the question onto the census, the memorandum marks yet another effort that would likely impact the balance of power in states and the House of Representatives, which are based on total population.

The courts will likely have the final say. The Constitution says congressional representation is apportioned based on "the whole Number of free Persons," not only those who are American citizens."The legal problem is that the 14th Amendment says that representatives shall be apportioned among the several states according to their respective numbers, counting the whole number of persons," said Joshua Geltzer of the Georgetown University Law Center.

"That means house seats are divvied up based on everyone present in the 50 states not just based on those lawfully present," he said.

In addition, Geltzer said, the Census doesn't currently ask whether someone is illegal. "Presumably the Trump administration will have to rely on a hodgepodge of other records to guess the population they intend to use for apportionment."Michael Li, who serves as senior counsel for the Brennan Center's Democracy Program, questioned how the federal government would make the determination on whether someone is illegal."

The Constitution requires counting everyone -- children, immigrants, everyone -- it doesn't have exclusions based on the legal status," Li said.