In March 2020, at the beginning of the COVID-19 pandemic, the Republican administration of then-President Donald Trump implemented sweeping restrictions at the U.S.-Mexico border through an order known as Title 42. At the time, health officials said the order, which allowed border agents to quickly expel migrants to Mexico, was needed to stem the spread of the virus in crowded border detention facilities. But some medical experts and immigration advocates saw the Title 42 restrictions not as a public health necessity, but as an extension of Trump's policy goals to stem both legal and illegal immigration.

When President Joe Biden, a Democrat, took office in January 2021 he promised to roll back many of his predecessor's hardline immigration policies. But he kept Title 42 in place. While Biden tried to end it at one point, he was blocked in court. On May 11, as the COVID health emergency officially ended, the administration lifted Title 42. It is now possible to see how it affected millions of migrants over the past three years.

Initially, Mexico only accepted Title 42 expulsions of certain nationalities: its own citizens and some Central Americans. Over time, more migrants from other parts of the Western Hemisphere, and the world – including far-flung places like Ukraine, Russia, Afghanistan and China – began arriving at the border. Most were processed into the United States under the previous statute, known as Title 8, which allows arriving migrants to seek asylum or other relief in U.S. immigration courts if they fear persecution at home.

Title 42 mostly applied to Mexican migrants

Mexicans are the nationality most frequently caught crossing the U.S.-Mexico border and also made up the largest group of quick Title 42 expulsions. Even before Title 42 was put in place, border agents were able to speedily turn back Mexican nationals under bilateral agreements.

Guatemala, Honduras and El Salvador

Before Title 42 was put in place, migrants from the Northern Triangle countries of El Salvador, Guatemala and Honduras made up a significant percentage of overall border crossings. After the order took effect, hundreds of thousands of people from these countries, including families, were turned back, often to dangerous cities just across the border in Mexico. Some, however, were given humanitarian exceptions and processed into the U.S. under Title 8, giving them a chance to seek asylum.

Immigration increases under Biden

Soon after Biden took office, the number of Venezuelans arriving at the U.S.-Mexico border began to rise, with many crossing through the perilous jungle region between Colombia and Panama, known as the Darien Gap, on foot. At the same time, Cubans, Haitians and Nicaraguans were arriving in larger numbers, but Mexico mostly refused to accept those nationalities under Title 42. That changed when Mexico agreed to accept the expulsions of Venezuelans late last year and of the other nationalities earlier this year. At the same time, the Biden administration opened up more legal pathways for those nationalities to apply for entry from abroad. Apprehensions of migrants from those countries dropped dramatically after those changes.

Nationalities not expelled under Title 42 arrive in larger numbers

For the most part, Mexico did not accept the returns of other nationalities, meaning that those who arrived at the border were processed under Title 8. So more people from more places began to arrive, making up a larger share of the overall apprehensions.

It remains to be seen what will happen next. As Title 42 was lifted on May 11, the Biden administration put in place a sweeping new regulation that bars most migrants from asylum if they cross the border illegally and have not sought protection in another country they passed through or used legal alternatives for U.S. admission. Those who fail to meet the higher standard can be quickly ordered deported and barred from U.S. entry for at least five years. Mexico agreed to accept Cubans, Haitians, Nicaraguans and Venezuelans deported from the United States after the end of Title 42, since it is not easy to send migrants back to those countries.

When he was in office, Trump tried to implement a measure similar to the Biden administration's new rule but was blocked in court. Immigration advocates have sued the current administration to try to stop the latest restriction, arguing the rule violates U.S. law and international agreements on the protection of refugees. The Biden administration says its asylum regulation is different from Trump’s because of new legal options for entry. Those options include applying for an appointment to approach a port of entry through an app called CBP One, as well as other humanitarian parole and refugee programs accessible from abroad. Now, thousands of migrants are in limbo, waiting to see how the radical swings in U.S. policy will affect their lives.