Customs and Border Protection (CBP) made 227,547 arrests in September at the U.S.–Mexico border... the most in history.

That was by far the highest number for a September, coming in at some 35,000 more than the first September under Biden, the previous record, and up 12 percent from August.

It was also one of the highest numbers in fiscal year 2022, despite September traditionally being one of the months in which illegal immigration slows because of weather and other patterns.

The number "reflects an accelerating pace of apprehensions when they should be declining seasonally," Steven Kopits, president of Princeton Policy Advisors, said in a statement.

"This speaks to both a strong U.S. labor market and deteriorating enforcement at the border."

Biden, a Democrat, reversed or weakened various Trump-era border policies, including halting construction of the border wall. His administration has also curtailed the deportation of illegal immigrants.

"Over the past 21 months, we have witnessed the devastating harm wrought by a rogue administration that is asserting near-dictatorial powers in a relentless effort to keep our borders open," R.J. Hauman, head of government relations and communications for the Federation for American Immigration Reform, said in a statement.