• Sen. JD Vance of Ohio claimed on CNBC's "Squawk Box" that 25 million unauthorized immigrants have entered the U.S. and that Democratic nominee Kamala Harris is to blame.
• Vance's figure inflates the facts, according to data from U.S. Customs and Border Protection and estimates from government agencies and other organizations.
• Vance, the running mate of Republican presidential nominee Donald Trump, was speaking against the notion that increased immigration to the U.S. has positive effects on the labor market.

Republican vice presidential nominee JD Vance made a dubious immigration claim Thursday as he blamed Vice President Kamala Harris for undocumented immigrants and asylum seekers entering the United States.

Vance, the Ohio senator and running mate to former President Donald Trump, said on CNBC's "Squawk Box" that Harris, the Democratic presidential nominee, "has flooded the country with 25 million illegal aliens."

But Vance's figure wildly inflates the facts, according to data from U.S. Customs and Border Protection and estimates from government agencies and other organizations that track border crossings and asylum claims.

Vance has spread the claim before. During an Aug. 28 speech in Wisconsin, Vance claimed Harris "let in 25 million illegal aliens." He specified in the same speech that those alleged 25 million people are currently "here in this country illegally."

Neither the Trump campaign nor Vance's spokesman replied to questions from CNBC about the source of the senator's numbers.

Setting aside the notion that Harris is personally responsible for the enforcement of U.S. immigration policy, Vance's numbers don't line up with the available data.

The Department of Homeland Security's Office of Homeland Security Statistics in April estimated that 11 million unauthorized immigrants were living in the U.S. as of Jan. 1, 2022.

That total marked a decline from an estimated 11.6 million unauthorized immigrants in the U.S. in 2010, but an increase from 10.5 million in January 2020, according to the office.

The nonpartisan Migration Policy Institute arrived at a similar figure, saying in March that it "estimates there were about 11.2 million unauthorized immigrants in the United States in 2021, up from 11 million in 2019."

"The several organizations that have long issued authoritative data based on rigorous methodologies estimate that the unauthorized population is more in the 11 million range," Michelle Mittelstadt, the Migration Policy Institute's communications director, told journalism nonprofit the Poynter Institute in June after Sen. Marco Rubio, R-Fla., made a claim similar to Vance's.

The Pew Research Center likewise estimated in July that, "The unauthorized immigrant population in the United States grew to 11.0 million in 2022."

Neither the U.S. Census nor any similar national survey collects data on the legal status of foreign-born residents living in the United States.

CBP reported nearly 10.2 million total encounters nationwide from February 2021 through July 2024.

But millions of those people were turned away in that time: CBP's data tallies nearly 2.5 million expulsions just under Title 42, the pandemic-era immigration restrictions that ended May 2023.

One encounter also does not necessarily equate to one person. Many of CBP's reported border encounters involve people who had previously tried to enter the U.S. within the prior year.

Vance's remarks Thursday came as he sought to rebut recent findings from investment firms such as Goldman Sachs that immigration has had a positive effect on the U.S. economy and the labor market.

"What that's actually led is communities like Springfield, Ohio, where you have 20,000 Haitians who have come in," Vance said on CNBC.

"Housing costs are unaffordable ... people can't afford to live a good life in this small Ohio town," he said.

"If the path to prosperity was flooding your nation with low-wage immigrants, then Springfield, Ohio, would be ... the most prosperous city in the world," Vance said. "America would be the most prosperous country in the world, because Kamala Harris has flooded the country with 25 million illegal aliens."

Vance's decision to invoke Springfield is notable: The city has come under the national spotlight after Trump and Vance both spread a baseless far-right conspiracy theory about Haitian immigrants stealing and eating Springfield residents' pets.

Trump repeated the claim during his presidential debate against Harris on Tuesday night.