NPR:

With preparations for the 2030 census already underway, President Trump said Thursday he has instructed his administration to start work on a “new” census.

According to a social media post by Trump, that census would exclude millions of people living in the country without legal status — an unprecedented change to how the country has conducted population tallies since the first U.S. census in 1790.

The 14th Amendment requires the “whole number of persons in each state” to be included in a key set of census numbers used to determine how presidents and members of Congress are elected.

The Trump administration has released no details about the plan. As a result, much is unclear, such as whether Trump — who, according to the Constitution, does not have final authority over the census — is referring to the regularly scheduled national head count in 2030 or an earlier tally.

Trump said he’s instructed the Commerce Department, which oversees the Census Bureau, to “immediately begin work” on a census using “the results and information gained from the Presidential Election of 2024.” It’s unclear why the election results would matter to the census.