If the underlying estimates hold, the shift would point to something the United States has not experienced on this scale in generations: net international migration turning negative.
In other words, more people may now be departing the United States than entering.
A Historic Reversal in the Foreign-Born Population
The foreign-born category is broader than illegal immigration. It includes naturalized American citizens, lawful permanent residents, temporary legal residents and immigrants living in the country illegally.
Still, the decline is striking.
According to the analysis, the estimated illegal immigrant population fell from approximately 15.8 million in January 2025 to about 13.5 million by July 2026.
That would represent a decline of roughly 2.3 million in only 18 months.
The broader foreign-born population reportedly declined by approximately 2.9 million over a similar period.
Such estimates come from household surveys and therefore carry statistical uncertainty. But the direction of the change coincides with an unmistakable transformation at the southern border following President Donald Trump’s return to office.
And that transformation has been dramatic.
From Record Border Encounters to a Fraction of the Biden-Era Peak
In September 2023, during the Biden administration, encounters at the southern border reached approximately 270,000 in a single month.
By February 2025, shortly after Trump returned to the White House, the figure had fallen to roughly 11,700.
That represents a decline of about 95 percent from the September 2023 level.
Trump entered office promising to restore aggressive immigration enforcement, end broad catch-and-release practices and make clear that illegally entering the United States would no longer provide an easy path into the country’s interior.
The administration argues that the strategy worked because prospective migrants quickly recognized that the incentives had changed.
DHS has also touted an extended streak in which Border Patrol released no illegal border crossers into the country under the policies that previously allowed many migrants to await immigration proceedings inside the United States.
DHS Secretary Markwayne Mullin credited Trump’s policies for the turnaround.
“Again this month, the results are clear: President Trump’s border security agenda is restoring order and putting the safety of the American people first,” Mullin said.
Trump went even further while discussing the border with GB News.
“I closed our border. We haven’t had a person come in illegally into our country through the southern border in 17 months now.”
The president’s sweeping claim goes beyond what border statistics alone can establish. But there is little question that reported encounters have collapsed from their Biden-era highs.
That matters because enforcement does not only affect people caught at the border.
It can also influence decisions made by people already living illegally inside the United States.
Enforcement Changes the Calculation
For four years, Republicans argued that weak enforcement created incentives for illegal immigration.
The Trump administration is now testing the opposite theory.
If migrants believe they will be detained rather than released, fewer may attempt the journey. And if people already in the country illegally believe removal is increasingly likely, some may choose to leave voluntarily.
That phenomenon — often described as “self-deportation” — could help explain part of the reported decline in the illegal immigrant population.
It is a fundamentally different approach from the Biden years.
Millions of migrant encounters were recorded during Biden’s presidency, while Republicans repeatedly accused the administration of allowing an overwhelmed immigration system to become a de facto pipeline into the country’s interior.
Trump returned to office promising to reverse that incentive structure.
The latest population estimates suggest the effects may extend far beyond the immediate decline in border crossings.
Crime Is Falling Too — But the Numbers Require Context
The administration’s supporters are also pointing to another major development: violent crime has continued falling.
FBI data showed a substantial decline in homicides in 2025, with the murder rate reaching levels not seen in decades.
That is welcome news for Americans regardless of party.
But falling homicide rates alone do not prove that immigration enforcement caused the decline. Crime is influenced by policing, demographics, local conditions, incarceration, economic factors and numerous other variables.
What can be said is that the border crackdown and falling violent crime are occurring at the same time — and Republicans who spent years demanding tougher enforcement will undoubtedly argue that the combination vindicates their broader public-safety agenda.
The political implications could be substantial.
Democrats spent much of the Biden era arguing over whether presidential authority alone could dramatically change conditions at the border.
Trump returned to office and immediately made immigration enforcement one of the central priorities of his administration.
Border encounters subsequently plunged.
The estimated illegal immigrant population declined.
And now analysts say net migration itself may have crossed into negative territory for the first time since the Great Depression era.
If that finding survives future revisions to Census data, it will represent more than another favorable immigration statistic for the White House.
It will mark one of the most dramatic reversals in modern American migration trends — and provide Trump with a powerful argument that Washington always possessed the ability to regain control of the border.
The missing ingredient, Republicans will argue, was the willingness to use it.
