US Vice President JD Vance has claimed the Trump administration has “sealed the border” and is driving undocumented immigrants out of the country after a new analysis found that the US foreign-born population fell by 2.9 million between January 2025 and July 2026.
US immigration crackdown: Vance says border ‘sealed’ as Trump steps up deportations. (AP Photo)
Vance made the claim on X on September 5, sharing an analysis by the Center for Immigration Studies (CIS), which examined data from the Census Bureau’s Current Population Survey. The analysis described the decline as unprecedented and said it indicated that net migration to the US had turned negative.
“We sealed the border and are getting illegal immigrants the hell out of our country,” Vance wrote.
The headline figure refers to the entire foreign-born population, not just undocumented immigrants.
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The Census Bureau defines foreign-born people as those who were not US citizens at birth, including people who later became US citizens through naturalization. The category also includes lawful permanent residents, temporary residents and undocumented immigrants.
CIS separately estimated that the undocumented population fell by about 2.3 million, from 15.8 million in January 2025 to 13.5 million in July 2026. That figure is an estimate, not a direct government count, and the change can reflect deportations, voluntary departures, legalization and deaths as well as new arrivals.
That distinction is important because Vance’s post directly linked the overall foreign-born decline to the removal of illegal immigrants.
CIS said the scale of the foreign-born decline suggests the US experienced negative net migration over the period, potentially marking the first such shift since the 1930s.
The broader Census picture does show a dramatic slowdown in international migration. The Census Bureau said net international migration declined across every state between 2024 and 2025, although all states still recorded positive net international migration in 2025.
Net international migration measures the difference between people entering and leaving the country. It is therefore different from the size of the foreign-born population.
The Census Bureau has also previously described the recent fall in net international migration as historic, making clear that changing migration flows are reshaping US population growth.
The data does not establish that all 2.9 million people left because of deportations. The foreign-born population can change because of several factors, including people leaving voluntarily, changes in legal status, deaths and movements in and out of the country.