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MATAMOROS, Mexico — Luis Martínez, 25, pulls up his shirt and tearfully shows two bullet holes and a prominent scar on his stomach.

"They shot me three times, two in my abdomen and one in my arm and another one in my back. I was with my grandmother, and four guys approached me," said Martínez, recounting a near-fatal holdup at the hands of a gang in his native Honduras.

"I can't return to my country, " Martínez added. "I can't even though it hurts me."

Martínez, who left Honduras to seek asylum in the U.S., has been living for over three months in a tent with his wife and two daughters a stone's throw from the U.S. border.

He's one of an estimated 2,500 migrants living in this camp in cramped, often squalid conditions as part of the U.S.'s "Remain in Mexico" program, or Migrant Protection Protocols (MPP), a 2019 policy that has already returned over 60,000 migrants to Mexico to wait after they make an initial asylum claim at the U.S. border.

On Wednesday, a Supreme Court decision dealt a blow to families like the Martínezes and civil rights advocates by allowing the program to continue while the justices decide whether they will hear an appeal of lower court rulings that declared the program illegal.

The 9th U.S. Circuit Court of Appeals in San Francisco had ruled against MPP for parts of the border on March 4, stating that the policy's enforcement would end Thursday unless the Supreme Court weighed in.

In its initial ruling, the court said it was "very clear" that MPP violated the law, adding, "It is equally clear that the MPP is causing extreme and irreversible harm to plaintiffs."

'I never imagined coming to this place'

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Martínez told NBC News that he hoped to seek a better life in the U.S. through legal processes, which is why he presented himself at the border seeking asylum.

Instead, he waits for his case to be called and watches the tent city become more overrun and increasingly precarious by the day.

"I never imagined coming here to this place. It was for my daughter. I want to give my daughter a better future, and my family," Martinez said.

Matamoros became well known after a tragic photo published last year reverberated around the globe. It was the image of Salvadoran migrant Óscar Alberto Martínez Ramírez and his nearly 2-year-old daughter, Valeria, whose bodies were found along the banks of the Rio Grande, where they had drowned.

Since then, the numbers in the camp have multiplied, and the situation is causing tension with local residents like Raul García, the owner of García's restaurant, which overlooks the encampments.

García called the sprawling tent city a "visual contamination," saying American tourists were no longer crossing the International Bridge from Brownsville in the same numbers they once were, which had an impact on businesses.

"We depend a lot on American tourism and more so in the winter season in Texas, which is in January, February and March," Garcia said. "It's very unpleasant for tourism —and for us —the citizens who live here in this part of the border, having them posted here about 50 meters from our businesses.

"I believe that they should be somewhere else," García added. "Another place, whether it be a field, with adequate infrastructure in that area, so that they can have a pleasant stay.

"This is the first time in my life that I've seen this situation," Garcia added.

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The Trump administration has described the policy as "enormously effective" in addressing immigration at the southern border.

Dozens of non-governmental organizations have been working in the camp since the policy was enacted. They fear that continuing the policy would further what they see as a humanitarian crisis, bringing the camp well beyond capacity.

"We are growing by between 50 and 100 people a day, but the conditions are going to get tighter and tighter," said Andrea Morris Rudnik, a co-founder of Team Brownsville, an organization dedicated to delivering humanitarian assistance to asylum seekers hoping to enter the United States.

"The Trump administration's policies are causing a level of suffering that we really don't know about in the United States," she said. "They are causing direct suffering to these people that are going through a process that we have set up. We've seen that these people are good people. Terrible, terrible things have happened to them."

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