“The census is a constitutionally mandated count of every person in the United States every 10 years, which was last conducted in 2020. A full census has never been conducted mid-decade in this manner, nor has one ever excluded noncitizens from the count.
Censuses are immensely important in American governance; each count determines how many House seats every state gets through a process called apportionment, and the results of the census help direct billions of dollars in federal, state and local funding.
Trump has been trying to include a citizenship question on the census since his first term, though the Supreme Court struck the effort down on procedural grounds in 2019. Apportionment numbers have also historically included people residing in the United States regardless of their immigration status.
A 2020 Pew Research Center report indicated removing noncitizens could cost multiple states House seats, including California and Texas.
Any attempt to do a mid-decade census would likely result in a flurry of legal and logistical challenges. Preparing for the decennial count takes multiple years, and planning for the 2030 census is already well underway.
It is unclear how the Trump administration plans to exclude undocumented people from the count, or if the president intended to just remove them from apportionment totals, which would also face legal hurdles.”
https://www.politico.com/news/2025/08/07/trump-new-census-00497025