A group of migrants are apprehended after crossing the border from Mexico in May. (Usbpa Edward Butron El Paso Sect/AFP/Getty Images)

Mexico’s president, Andrés Manuel López Obrador, ran for office preaching the need to respect the rights of migrants. But since he took office in December, his administration has attempted to prove both to the Trump administration and to Central American asylum seekers that it will not allow unencumbered passage through Mexico.

 For years before López Obrador took office, Mexico deported large numbers of Central American migrants — more even than the United States. From January 2015 to September 2018, Mexico deported 436,125 Guatemalans, Salvadorans and Hondurans. 

Deportations by Mexican authorities have increased compared with the same period last year, according to the latest statistics. Between January and April, Mexico deported more than 37,000 migrants, according to its immigration agency. It has become more antagonistic toward migrant caravans, which last year traveled through Mexico with relative freedom. 

 Now, many of those traveling with caravans are forced to apply for transit passes before they can continue, a process that has dramatically slowed the movement of such groups. In recent months, those migrants have protested in front of Mexico’s immigration offices, calling the country xenophobic. 

 “We have to make a response because there cannot continue to be hundreds of thousands of migrants passing through Mexico and arriving at the northern border,” Interior Minister Olga Sánchez Cordero said when a caravan began to form in March.

In a letter to Trump on Thursday, López Obrador wrote that the White House knew Mexico was working to avoid “passage through our country.”

But tens of thousands of Central Americans, mostly from Guatemala and Honduras and mostly traveling with smugglers, still journey through Mexico each month. U.S. officials say Mexico is not doing enough to secure its southern border with Guatemala, or to crack down on the private bus companies that ferry migrants through the country, usually accompanied by their smugglers.

“To address this crisis, Mexico must take significant action to secure their southern border, stop the unlawful flow of migrants across their territory, and attack the criminal groups preying on vulnerable migrants and profiting from these smuggling enterprises,” said acting Homeland Security Secretary Kevin McAleenan. 

Mexico’s 570-mile border with Guatemala is largely porous, with people visibly swimming back and forth across the Suchiate River that separates the two countries, and with Mexican officials typically looking the other way. Over the past year, smugglers have turned to informal border crossings in the southern Mexican state of Chiapas, which migrants traverse on their way to main bus routes. 

“We fully believe they have the ability to stop people coming from their southern border,” McAleenan said. 

Many of the migrants are traveling with their families. More than 75,000 families have traveled through Mexico on their way to the U.S. border in May, according to McAleenan.

Mexican officials say that while the country’s southern border remains porous, immigration agents and other security officials have set up highway checkpoints along main corridors, where buses and trailers are inspected. In some cases, though, Mexican immigration officials have been found accepting bribes in exchange for allowing the passage of those without documentation. 

Perhaps most dramatically, the United States in recent months has begun forcing many asylum applicants to wait in Mexico while their cases are processed. More than 5,000 people have been processed so far under the “Remain in Mexico” policy, which is meant to keep migrants from living and working in the United States while they await their court dates.

The Mexican government said it had no choice but to comply with the policy, and it has accepted the asylum seekers, who in many cases are housed and fed in Mexican migrant shelters.