New report reveals illegal immigrant population hit new high during Biden-era crisis

The report was produced by the Federation for American Immigration Reform (FAIR), which argues for lower levels of immigration overall. It estimates that, as of March 2025, there are approximately 18.6 million illegal immigrants living in the U.S.

FAIR estimates that there were around 11.7 million illegal immigrants in 2013.

The group includes, as an illegal immigrant, anyone who does not have legal status like a visa or permanent residency, and notably also includes those who may be in the country illegally but given a lawful presence, like Temporary Protected Status or humanitarian parole.

FAIR argues that even though they are described as having a "lawful presence," they do not have legal status and therefore cannot be counted as being in the country legally.

"Counting individuals in these situations as 'legal immigrants' or 'lawful residents' would be both incorrect and a biased mischaracterization of immigration law," the group argues.

The report estimates the total number of illegal immigrants by using Census Data and compensating for what it argues is a history of undercounting those who arrive illegally, calculating an undercount of around 40%.

The report also concedes that "estimating the size, distribution, and characteristics of the illegal alien population is an inexact science."

"In truth, we do not know exactly how many people cross the border illegally and evade immigration authorities, nor can anyone accurately quantify overstays or gotaways. We can only estimate these figures based on annual and monthly census data," the report says.

It argues that key factors driving the surge in numbers were Biden-era policies, including at the border, the release of migrants into the U.S. and what it claims was an "abuse" of parole authority.

The administration has since been touting a sharp drop in numbers at the border.

In February, there were just 8,326 southern border encounters, down from 189,913 in February 2024. The administration has so far removed more than 55,000 illegal immigrants from the U.S.

"They heard my words, and they chose not to come."