President Donald Trump signed a memorandum on Thursday directing the Commerce Department to conduct a new national census, citing an “urgent need” to obtain an updated count of citizens and to “quantify the impact of millions of illegal immigrants who were not properly captured in 2020.” The document instructs Commerce Secretary Carlos Gutierrez to submit a plan within 90 days for a supplemental enumeration that (1) distinguishes citizens from non-citizens and (2) excludes people in the country unlawfully from the base figures used in federal population tables. White House officials said the president acted after internal reviews concluded that continuing inflows across the southern border have rendered many resource-allocation formulas “obsolete.”