The Migrant Protection Protocols (MPP), commonly known as "Remain in Mexico," is a U.S. Department of Homeland Security program first announced in December 2018 and implemented beginning in January 2019 under the Trump administration. Under MPP, certain non-Mexican nationals arriving at the U.S. southern border to seek asylum were returned to Mexico for the duration of their U.S. immigration court proceedings, rather than being detained in the United States or released into the country pending hearings.
The policy was grounded in the U.S. government's interpretation of Section 235(b)(2)(C) of the Immigration and Nationality Act, which permits the return of certain arriving aliens to a contiguous country. Mexico agreed to receive returnees on humanitarian grounds, though it was not formally a party to a bilateral treaty on the matter.
MPP has been politically and legally contentious. Critics—including the UNHCR, Human Rights Watch, and Amnesty International—documented kidnappings, assaults, and extortion targeting migrants waiting in Mexican border cities such as Ciudad Juárez, Tijuana, and Matamoros, and argued the policy undermined obligations under the 1951 Refugee Convention's principle of non-refoulement. Supporters argued it deterred meritless asylum claims and reduced strain on U.S. detention capacity.
The Biden administration suspended new enrollments in January 2021 and formally terminated the program later that year. After litigation by Texas and Missouri, a federal district court ordered MPP's reinstatement, and DHS partially restarted the program in December 2021. In Biden v. Texas (2022), the U.S. Supreme Court held 5–4 that the Biden administration's termination did not violate the INA, allowing the program to be wound down again.
Key features included:
- Application primarily to Spanish-speaking nationals from Central and South America
- Exemptions for unaccompanied minors and certain vulnerable populations
- Hearings held at U.S. immigration courts, sometimes via tent facilities near the border
Example
In January 2019, the first asylum seeker was returned to Tijuana under MPP, beginning a program that would enroll roughly 70,000 migrants before its initial suspension in 2021.
Frequently asked questions
No. After the Supreme Court's 2022 ruling in Biden v. Texas, the Biden administration wound down the program, and new enrollments ended.
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