President Donald Trump on Thursday directed the Department of Commerce to begin work on what he called a “new and highly accurate” U.S. census that will exclude people living in the country without legal authorization. In a post on his Truth Social platform, Trump said the count should rely on “modern day facts and figures” and draw on information from the 2024 presidential election. The order revives an effort from Trump’s first term, when he tried to add a citizenship question to the 2020 census and later issued a memorandum to omit undocumented migrants from population tallies. The Supreme Court blocked the question in 2019, and President Joe Biden rescinded the exclusion policy in 2021 after taking office. Census data underpin the apportionment of seats in the House of Representatives, Electoral College votes and the distribution of hundreds of billions of dollars in federal funding. Removing an estimated 11 million undocumented migrants could cost states with large immigrant populations such as California, Texas, Florida and New York congressional representation, while benefiting others with fewer non-citizen residents. Constitutional lawyers noted that Article I, Section 2 requires an “actual enumeration” of all persons every 10 years and that only Congress can substantially alter the census. Civil-rights groups and several states are expected to challenge the directive, setting up another legal confrontation over the scope of presidential power. The next decennial census is scheduled for 2030, and the Commerce Department has not detailed a timeline or methodology for any additional count.