Migrant Flow Returns to Traditional Demographic Patterns under Trump II

I recently analyzed CBP’s FY 2025 encounter statistics and noted that Border Patrol apprehensions last fiscal year reached their lowest level since FY 1970. As importantly, however, those statistics reveal the flow of migrants coming illegally across the Southwest border is returning to traditional demographic patterns under Trump II, largely composed of Mexican nationals with lesser numbers of nationals of the “Northern Triangle” countries of Central America (El Salvador, Guatemala, and Honduras) also in the mix. While it might be premature, the global migrant influx spurred by President Biden’s border policies appears to have ended. 

“The Biden Border Crisis Goes Global”

In a July 2021 article, “The Biden Border Crisis Goes Global as Aliens Enter Illegally from Farther Away”, I examined CBP statistics for the first four months of the last administration and noted a “grim reality”: “More aliens are coming from farther away to enter the United States illegally – a lot more.” 

As I explained, prior to FY 2009, nearly all (90 percent plus) of the illegal migrants apprehended at the Southwest border came from Mexico, and most were single adult males arriving here for seasonal work. The rest were collectively referred to as “OTMs” – Other Than Mexicans. 

By FY 2012, however, aliens apprehended at the Southwest border from the Northern Triangle climbed to nearly a quarter of the total, and in FY 2014, for the first time in history, apprehensions of Northern Triangle migrants surpassed Mexican apprehensions at the Southwest border, constituting nearly half (49.6 percent) of all total Border Patrol encounters that year.

That trend increased, and by FY 2019, more than 71 percent of Southwest border apprehensions involved aliens from the three Northern Triangle countries, nearly 608,000 aliens in total. 

That Northern Triangle surge prompted the first Trump administration to institute “Remain in Mexico”, under which illegal migrants – Mexicans, OTMs, and Northern Triangle migrants – who claimed asylum were sent back to Mexico to await their removal proceedings.

Remain in Mexico worked, and by February 2020, a majority (55.6 percent) of all apprehensions again involved Mexican nationals. And when the Covid-19 pandemic was declared one month later, CDC issued the first of its “Title 42” orders directing the expulsion of all those who entered illegally.

If the Biden administration had intended to demolish the immigration system, there’s not much more it could have done to accomplish that goal. 

The pandemic shut down most global travel, which at least at first made it all but impossible for OTM migrants to traverse Mexico on their way to the United States. Of the 16,180 apprehensions at the Southwest border in April 2020, 69 percent involved Mexican nationals.

Under Biden, however, Mexico increasingly refused to accept OTM migrants expelled from the United States under Title 42, and by the time those orders were rescinded in May 2023 was only accepting its own nationals and a few who hailed from the Northern Triangle countries. 

That, coupled with the Biden administration’s refusal to detain most illegal entrants not expelled under Title 42, is why the “border crisis” began “going global” by July 2021. Simply put, people around the world saw an opportunity to live and work in the United States and many took it. 

Things only got worse from there, and by December 2023 – a month Border Patrol agents apprehended almost 250,000 illegal entrants at the Southwest border – nearly 134,000 of them (53.7 percent) were not only OTMs, but “other than Northern Triangle” nationals (ONTs) as well. 

That was a problem, as there are many reasons why it’s harder for DHS to remove OTMs/ONTs than nationals of Mexico and the Northern Triangle.

Generally, their asylum claims (to the extent they appear in immigration court) are unique and country-specific, travel costs to remove them are much higher, and many are from “recalcitrant” countries (including Cuba, Venezuela, and China) that either refuse or delay accepting their deported nationals.

It’s much easier, on the other hand, for DHS to remove illegal Mexican nationals; agents can generally just process and return them in about 8 hours through the closest port of entry. Northern Triangle returns are slightly more complicated, but in many cases Mexican authorities will take them back, as well. 

Not to cast aspersions, but if the Biden administration had intended to demolish the immigration system, there’s not much more it could have done to accomplish that goal. 

FY 2025 Patterns

The bad news is that many of the 2.525 million-plus OTM/ONT migrants apprehended at the Southwest border between FY 2022 and FY 2024 who weren’t expelled under Title 42 are still here and may be indefinitely. 

The good news is that few new OTM/ONT migrants came illegally over the Southwest border in FY 2025, and the even better news is that in recent months, most apprehended illegal migrants have been Mexican nationals. 

This Trump II demographic reset is reflected in the following graph of Border Patrol’s total FY 2025 Southwest border apprehensions and Northern Triangle and Mexican apprehensions (respectively), by month:

As you can see, many (34 percent) of the migrants apprehended at the Southwest border in the last three full months of the Biden administration, October through December 2024, were OTMs/ONTs.

By February, the first full month of Trump II, OTM/ONT apprehensions fell to 22 percent of the monthly total, and then to 14.3 percent in March. 

In the last three months of the fiscal year (July through September), OTMs/ONTs were involved in less than 13 percent of Southwest border apprehensions; Mexican nationals accounted for 69 percent, and Northern Triangle nationals an additional 18 percent. 

The Trump II Plan

By working with the Mexican government to secure that nation’s migrant routes north, the Trump II administration has made it more difficult for OTMs/ONTs to arrive at our Southwest border. 

And those who do make it aren’t finding the quick-release policies their predecessors enjoyed under Biden. Between October and December 2024, Border Patrol agents released more than 24,000 illegal migrants on their own recognizance. Since May, agents haven’t released anybody and only cut loose eight illegal migrants in March and April.

The Biden administration should have known its policies were sending a message to the world that our Southwest border was open to all comers. Millions globally took them up on the offer, but now that the message – and the messenger – have changed, most would-be migrants are staying closer to home.