With Trump-appointed judges and the Supreme court forcing the Biden administration to re-start the Migrant Protection Protocols (MPP, or “Remain in Mexico”) program at the border, watch what happens to migrants according to their nationality.

If Remain in Mexico gets implemented at even some of the intensity that it was during the Trump years, and if the Biden administration at the same time continues expelling many migrants—including asylum seekers—under the Title 42 pandemic authority, then something ugly might happen.

Basically, we can group affected migrants into three types of nationalities.

First, citizens of Mexico have always had a hard time making asylum cases in the United States. They weren’t subject to “Remain in Mexico” but were massively expelled back to Mexico after the pandemic measures went into effect in March 2020. Here’s all Mexican citizens encountered at the border, and then those traveling as families (parents with children):

Second, citizens of the “Northern Triangle” countries—El Salvador, Guatemala, and Honduras—were massively placed into “Remain in Mexico.” Then, after March 2020—because Mexico agreed to take most of them—they’ve been massively expelled under Title 42, also. No matter what happens, they’ve had a slim chance at due process when they ask for protection in the United States.

Attorneys who work with expelled migrants tell me that they hear constant horror stories from parents with kids stuck in Mexican border cities about what happens to them at the hands of criminal groups after they’re expelled.

Third, citizens of several other Spanish and Portuguese-speaking countries were subject to “Remain in Mexico,” and many ended up in Mexican border towns. But they haven’t been expelled in large numbers under Title 42 for logistical or consular reasons.

Mexico won’t take them as expulsions across the land border. It’s expensive to fly them back to their countries of origin, and some of their governments (Cuba, Nicaragua, Venezuela) have poor relations with the United States.

They’re not as much part of this story, but it’s worth mentioning that there are a few other countries, particularly Haiti, whose citizens didn’t have to remain in Mexico, but in some cases have been expelled by air.

In July, 23 percent of migrants—and 31 percent of families—encountered at the U.S.-Mexico border were from countries whose citizens weren’t being massively expelled, but would have had to “remain in Mexico” when Trump was president. Right now, few are being expelled.

72 percent of migrants—63 percent of families—were from Mexico and Central America, and still often subject to expulsion under the Title 42 pandemic order.

If they get carried out together right now, Remain in Mexico combined with Title 42 would create a very ugly two-tiered system.

Keep in mind that Title 42 is even worse than Remain in Mexico because it doesn’t even give asylum seekers a court date in the United States. So if the courts force a true restart of Remain in Mexico, nearly one-third of families might get shoved into Mexico with a court date, while most of the rest wouldn’t even get that. That’s a new level of malice.