President Trump on Tuesday signed an executive order to exclude undocumented individuals from the 2020 census. The census, conducted every 10 years, tracks the U.S. population and determines how many U.S. House Representatives are allocated to each state.

“For the purpose of the reapportionment of Representatives following the 2020 census, it is the policy of the United States to exclude from the apportionment base aliens who are not in a lawful immigration status under the Immigration and Nationality Act,” the memo says. “Excluding these illegal aliens from the apportionment base is more consonant with the principles of representative democracy underpinning our system of Government.”

The move is considered an attempt by the Trump administration to undermine the political power of immigrants. The American Civil Liberties Union has vowed to sue the Trump administration over the order.

“Trump tried to add a citizenship question to the census and lost in the Supreme Court. His latest attempt to weaponize the census for an attack on immigrant communities WILL be found unconstitutional,” the ACLU said in a tweet. “We’ll see him in court — and win — again.”

The census has traditionally counted every person living in the U.S., not just citizens but also non-citizen legal residents and unauthorized legal residents. Trump had attempted to include a citizenship question on the 2020 census but the Supreme Court ruled against it.

"The Constitution says count 'persons' not citizens," Joyce Alene, a law professor at the University of Michigan tweeted. "His unconstitutional EO today, directing a count of only citizens is red meat for his base & an effort to distract from Covid & his other disasters."