One major impact of the current Trump administration’s policies on illegal immigration has been a startling plunge in the foreign-born population in the U.S., and it’s the largest six-month decline ever in the same year, according to a new report from the Center for Immigration Studies (CIS).
The foreign-born population declined an astonishing 2.2 million from January to July, CIS reported, estimating the number of illegal immigrants fell by 1.6 million in the same period. CIS based its estimates on an analysis of raw data from the Bureau of Labor Statistics’ (BLS) Current Population Survey (CPS). CIS also estimated the total illegal immigrant population at 14.2 million in July based on the January 2025 CPS. CIS defined illegal immigrants as people with “pending defensive asylum applications, those with Deferred Action for Childhood Arrivals (DACA), those with Temporary Protected Status (TPS), and parolees.”
CIS explained that the weak job growth evidenced in the Bureau of Labor Statistics’ data was likely due to “the falloff in the number of employed illegal immigrants in the country due to their heading home.” In March, CIS posited that the number of foreign-born people in the U.S. hit an all-time high.
CIS buttressed its argument that the harsh decline in the number of foreign-born represented the exit of illegal immigrants by noting, “The number of non-citizens is down 2.6 million, while the number of naturalized citizens is actually up 373,000. … Since illegal immigrants are not citizens, the decline in the number of people who are not American citizens is consistent with what would be expected if the number of illegal immigrants fell.” They added, “The fact that there has not been a decline in naturalized citizens or even long-time non-citizens is an indication that the foreign-born in general are still willing to respond and identify as such.”
“From January to July 2025, the number of post-1980 Latin American non-citizens declined by 1.6 million or about 10 percent. Although this population accounts for a little less than one-third of the immigrant population, they represent 73 percent of the decline in the total foreign-born in the last six months,” CIS reported, adding, “These results strongly support the idea that the election of Donald Trump, his rhetoric, high-profile enforcement actions, and border policies have caused a large number of illegal immigrants to leave the country and many fewer to enter.”
