WASHINGTON – A historic surge in migration during Joe Biden's presidency led to attacks as he ran for re-election. Donald Trump and his Republican colleagues blamed Democrats for the increasing number of people crossing the US-Mexico border.
After campaigning on promises to secure the border and deport undocumented immigrants, President-elect Trump is poised to take office Monday amid a sharp decline in border crossings.
Here are five key facts about migration across the U.S.-Mexico border in recent years.
1. The number of arrivals at the border is at its lowest since Trump took office
When Trump left office in January 2021, more than 50 people were stopped at the southern border 78,000 times this month, according to figures from U.S. Customs and Border Protection. That's approximate in comparison 96,000 stops last month. The highest monthly total during the Biden administration was nearly 302,000 in December 2023, and Trump's highest total was just above that 144,000 in May 2019.
These numbers include arrivals at land ports of entry, where asylum seekers await appointments for legal entry, as well as those caught crossing the border illegally elsewhere. Figures from November and December showed for the first time that more migrants were processed through ports of entry than those arrested after entering the United States illegally.
In June, the Biden administration began effectively blocking migrants from seeking asylum along the U.S. border with Mexico. The restrictions do not apply to those entering through official ports of entry or using other legal means.
For parts of last year, San Diego became the Top travel destination for For the first time in decades, illegal border crossings are occurring along the U.S.-Mexico border. The change reflects how smuggling routes, once uniform for many years, have begun to shift every few months since 2021. This is partly due to the increase in global migration to the US following the pandemic
The San Diego region had 10,117 border apprehensions in December – the second highest number after the Rio Grande Valley in Texas – although that is down 70% from a year ago.
2. There was no major increase in border arrivals before Trump's inauguration
In the weeks before Trump's inauguration, there was little change in migrant arrivals in most regions across the border. But Senior Border Patrol Agent Gloria Chavez of the Rio Grande Valley Sector in South Texas, who posts local arrest numbers on social media every week, reported 1,206 migrant stops on the last weekend of December and 1,276 the weekend before. That is twice as much as in the last few weeks fewer than 600 arrests.
“It is the first quantitative indicator of an increase in migration since the US election, which raised expectations – as yet unfulfilled – that many migrants could rush to the United States before Election Day.” Adam Isacson, director of defense oversight at the advocacy group Washington Office on Latin Americawrote in a recent newsletter.
That trend appeared to have subsided in the new year, Chavez reported 669 arrests the weekend that ended January 5th and 699 arrests the weekend that ended January 12th.
Isacson noted that asylum seekers entered the U.S. in a rush in 2016, before Trump began his first term. But border policy is different now because the Biden administration's rules already prevent most people who enter illegally from being eligible for asylum.
“Your only hope is not to get caught,” he said. “Some people might try, and if they succeed, they won’t show up in the numbers.”
Aaron Reichlin-Melnick, a senior fellow at the left-leaning American Immigration Council, said tens of thousands of migrants were waiting in Mexico.
“Today it is more difficult for migrants to get to the border and apply for asylum than at any time in modern U.S. history,” he said. “Despite this massive expansion of border infrastructure, the United States continues to be a place of safety and security in the eyes of people around the world.”
3. The US border used to attract mostly Mexican and Central American migrants. People from all over the world are now flocking here
The US has attracted migrants from its southern neighbor in the past. Although Mexicans still make up the largest share of those seeking entry, the number of arrivals from other countries has skyrocketed over time. During Trump's first term, people from Honduras, Guatemala and El Salvador flocked to the U.S. border because of instability in their home countries.
That started to change around 2019. During Biden's presidency, increasing numbers of people arrived from Venezuela, Cuba and Colombia. People also came from further afield – Afghanistan, Ukraine and China.
The San Diego region has the border that is considered the most international, attracting people from all over the world.
Chinese migrants seeking work and freedom from the repressive government arrived in record numbers – from just 949 arrests in fiscal 2022 to over 37,000 in the last fiscal year. Republicans seized on the surge, portraying it as a national security issue.
The numbers began falling last year after the Biden administration imposed asylum restrictions and Ecuador began requiring Chinese nationals to have visas to fly there.
4. Immigrant detention has increased again since COVID-19 receded
The government's actions to detain people who violate immigration laws have fluctuated wildly in recent years. During Trump's first term, the population detained by Immigration and Customs Enforcement reached an all-time high of more than 55,000 people.
As COVID-19 spread in prisons and killed inmates, courts ordered some immigrant detention centers to reduce their populations. The number of people incarcerated reached a low of around 13,000 people in February 2021, a month after Biden took office. (The Adelanto ICE Detention Facility east of Los Angeles has remained under a COVID-era court order This prevented new detainees and reduced the population of the nearly 2,000-bed facility to just two people.)
According to TRAC, a nonpartisan data research organization, as of December 29, more than 39,000 people (most of whom have no criminal record) are being held in civilian immigration detention centers. This number has remained fairly consistent over the past year, generally fluctuating between 35,000 and just under 40,000 since the end of 2023.
The numbers are widely expected to rise again after Trump takes office as he works to make good on his promise of mass deportations.
5. Historic newcomers under the Biden administration added to the already massive immigration court backlog
Immigrants facing deportation proceedings can argue their case before an immigration judge. Given the historic arrival of migrants under the Biden administration, the immigration court backlog now stands at more than 3.7 million pending cases, according to TRAC.
Biden inherited an already overwhelmed immigration court system with 1.3 million cases. When Trump took office in 2017, just over 542,000 cases were still pending.
In fiscal year 2024, immigration courts completed more than 900,000 cases, the most in a single year. New cases have fallen sharply as fewer immigrants are being processed at the border.
Los Angeles County has nearly 115,000 cases, second only to Miami-Dade County. Experts say the backlog cannot be eliminated without funding hundreds more immigration judges and support staff and system reforms.