U.S. Department of Homeland Security Secretary Kristi Noem paints a section of the border barrier in New Mexico in August to prevent rust and make it hotter to prevent climbing. Declines in immigration contributed to a low population gain in the United States last year. (Photo by Danielle Prokop/Source NM)

A drop in immigration amid President Donald Trump’s enforcement crackdown led to historically slow population growth in the United States last year.

Activity at the southern border is at a historic low. The population change reflects the last months of the Biden administration, when immigration controls began to tighten, and the first months of the Trump administration’s massive anti-immigration and deportation agenda.

Five states lost population, according to the new Census Bureau estimates released Jan. 27 covering changes between mid-2024 and mid-2025. The changes suggest Texas and Florida could gain congressional seats at the expense of California, Illinois and New York.

States that did gain population were concentrated in the South, where numbers appear to give Republican states in the region a political edge halfway through the decade. 

An analysis by Jonathan Cervas at Carnegie Mellon University predicted four more seats in Congress after the 2030 census for Texas and Florida, with losses of four seats in California and two each in New York and Illinois. Cervas is an assistant teaching professor who researches representation and redistricting. 

“We are still a long way off from 2030, so there is a lot of uncertainty in these projections,” Cervas said, adding that California’s loss in the next decade could be only two or three seats.

Another expert, redistricting consultant Kimball Brace of Virginia, said he was suspicious of the sudden drop in California’s population. Earlier projections had the state losing only one seat after 2030, he said. 

“This acceleration in California’s population loss is not something that was in the projections at all,” Brace said. “I’ve got to be a little bit skeptical in terms of the numbers. It shows a significant difference in what we’ve seen in the early part of the decade.”

Brace was still working on his own analysis. William Frey, a demographer at The Brookings Institution, said net immigration was about 1.3 million nationally for the year, down by more than half from the year before.

“As a result most states showed slower growth or greater declines,” Frey said. California had about 200,000 fewer immigrants than the previous year, similar to Texas and New York, though those two states eked out populations gains anyway because of people moving in and births 

Texas and North Carolina gained the most people between mid-2024 and mid-2025, while California and Hawaii lost the most. 

Nationally, the population increased only about 1.7 million, or half a percentage point, to about 341.8 million. It was the lowest increase of the decade and the smallest gain since the pandemic sharply cut growth in 2020 and 2021. Growth was just 1.4 million between mid-2019 and mid-2020, and only about 500,000 between mid-2020 and mid-2021. Before that, national population growth was below 2 million only twice since 1975. 

Among the states, Texas gained about 391,000 in population, up 1.2%, followed in the top 5 by Florida (197,000, or .8%, North Carolina (146,000, or 1.3%), Georgia (99,000, or .9%) and South Carolina (80,000, or 1.5%).

California went from one of the largest increases the previous year to the greatest population loss, about 9,500, less than .1%,  followed by Hawaii (down 2,000, or .1%), Vermont (down 1,900 or 0.3%), New Mexico (down  1,300, or 0.1%) and West Virginia (down 1,300 or .1%). 

Vermont had the largest percentage decrease and South Carolina had the largest increase. 

Stateline reporter Tim Henderson can be reached at thenderson@stateline.org.