Brownsville, Texas (CNN) In a trailer located a stone's throw away from Mexico, a mom cradled her two young sons, a little girl sat on her dad's lap, and a boy swung his legs, his feet unable to touch the floor.

In all, 23 migrants sat in silence looking at a large TV screen displaying an immigration judge who was located some 30 miles away.

Over the course of the morning, each migrant approached a rectangular table set up at the front of the room and pleaded with Judge Julian Castaneda, through the interpreter sitting beside him, to stay in the United States. Of the 47 migrants expected to attend the hearing, only 23 showed up.

The trailer is one of many makeshift courtrooms set up in Brownsville, just across from Matamoros, Mexico, and were only recently opened up to journalists. The so-called tent courts ( another is in Laredo, Texas ) are being used to hear cases of migrants forced to stay in Mexico until their immigration proceedings in the United States. When the hearing wraps, they're generally sent back to Mexico to wait for their next court date, which can be weeks or months away.

Forcing migrants, many of whom are from Central America, to Mexico marks an unprecedented shift in US asylum policy. Instead of living in the US as they work their way through the immigration court process, migrants are required to stay in Mexico, under the policy formally known as the Migrant Protection Protocols.

While they wait in Mexico, migrants have had to weather difficult and dangerous conditions in encampments along the border, living under tents or tarps and using makeshift bathrooms. The deteriorating situation has resulted in children crossing the border alone who had been waiting with a family member and has posed challenges to those trying to make their hearings

Despite ongoing legal challenges, a federal appeals court allowed the policy to continue.

Until recently, the administration largely limited access to the facilities to attorneys representing migrants, while observers had to watch proceedings from the judge's courtroom miles away. CNN sat in one of the morning hearings at the Brownsville tent court earlier this month.

The facilities, which can be spotted from the Mexico side of the border, are lined with artificial grass, and a mix of waiting rooms and makeshift courtrooms. Porta-potties are available for migrants and visitors. Some of those porta potties have signs stamped on them saying "do not throw diapers in the bathroom," an indication of the varying ages of those who pass through.

Migrants scheduled for an 8:30 a.m. hearing are required to present themselves at the border a few hours prior. Once processed, migrants shuffle in single-file lines, escorted by staff to their respective hearing room. There, they make their case before the judge to stay in the United States.

"I don't want to be deported to Venezuela because I'm being subjected to political persecution in that country," a Venezuelan man told the judge during a recent morning session.

Migrants in the hearing room couldn't see the Immigration and Customs Enforcement attorney who was in the same room as Judge Castaneda and interpreter. Every so often, the ICE attorney would chime in, but migrants were unable to see or understand him. The interpreter didn't translate communication between the attorney and the judge, leaving those watching and participating via the TV screen in the dark.

In a more typical immigration court hearing, the migrant would be in the same room as the attorney, immigration judge and interpreter.

"This is unlike other video teleconferencing set ups in immigration court that the ICE trial attorney is not visible to the respondent," said Laura Lynch, senior policy counsel for the American Immigration Lawyers Association. "It's very confusing as to who's prosecuting the respondent."

Since its implementation about a year ago, more than 57,000 migrants have been sent back to Mexico until their court date in the US.

Department of Homeland Security spokesperson Heather Swift called the policy "an effective tool to address the ongoing crisis at the southwest border." But lawyers and advocates argue that the policy makes it harder for those with legitimate asylum claims to get refuge in the United States.

Migrants who are applying for asylum in the United States go through a processing area at a tent courtroom, Tuesday, Sept. 17, 2019, in Laredo, Texas.

The immigration court system is run by the US Justice Department and operates differently than the federal or state court system. For example, immigrants in the immigration court system are not provided a government-appointed counsel , as they would be in other court settings.

The tent courts also underscore the concerns lawyers have raised for years, including ensuring access to counsel to migrants and conducting hearings over sensitive matters via video teleconferencing.

Kathryn Mattingly, a spokeswoman for the Executive Office for Immigration Review, an office within the Justice Department that oversees the nation's immigration courts, said in a statement to CNN that "All immigration judges are prepared to hear any case at any time, including via VTC."

Migrants struggle to find attorneys legal representation

Migrants waiting in Mexico face the challenge of finding and obtaining legal representation. While organizations and legal service providers have tried to assist, they're "completely overwhelmed," Lynch said.

"This program is definitely an additional burden for those organizations and trying to find ways to facilitate legal access for these individuals," Lynch added.

Attorneys in these cases are representing clients for proceedings in the United States, but as they go through that process, the clients are required to stay in Mexico, which can make communicating about the details of the case challenging.

Migrants told Castaneda during a hearing CNN attended that they didn't have an attorney. That can be an impediment for those trying to seek refuge in the United States, given the complicated nature of immigration proceedings. Conducting hearings via video teleconferencing exacerbates those issues, Lynch says.

Edgar Arias, a Venezuelan migrant, said he couldn't afford counsel. "We don't have money," he told CNN. His next court hearing in the US is in April.

Migrants will attend a series of hearings before a decision is made on their case.

In a morning session earlier this month, four master calendar hearings, the first hearing in removal proceedings, and seven merit hearings, where asylum seekers present their claims, were scheduled.

A Miami-based lawyer waiting for a client's merit hearing said that the migrants her firm represents have been "discouraged" by the administration's policy.

"I don't feel it's the same experience" as other immigration court settings, the lawyer told CNN.

'They sleep under that tent'

Over a sea of tents, makeshift bathrooms, and tangled clotheslines, the temporary facilities where the administration has set up courtrooms can be spotted in the distance.

Migrants, many of whom are from Central America, have journeyed to the US-Mexico border to seek asylum. CNN talked to some of those waiting in a camp in Matamoros, who said they were fleeing dangerous conditions in their home countries.

A new tent court, Tuesday, Sept. 17, 2019, in Laredo, Texas.

The Trump administration had said that it planned to expedite hearings for migrants who fell under the policy. But even so, it takes time for an individual's case to be resolved. And in the interim, migrants are often waiting in squalid and unsafe conditions in Mexico.

Mikaela Hernandez, who came from Guatemala, told CNN that she planned to claim asylum in the United States and reunite with her husband in America. She's been at the camp for four months and attended immigration court four times. She has a follow up hearing in February.

"All of us ask God that he help us and open doors for us," she said, as her two-year-old daughter latched on to her leg.

Eighteen members of Congress descended on the camp this month to assess the administration's "remain in Mexico" policy, a few days after the House Judiciary Committee announced an investigation into the policy. The Democratic lawmakers navigated through the tents, makeshift food stalls and clotheslines, interacting with migrants as they went.

Democratic Rep. Rosa DeLauro, of Connecticut, expressed outrage over the program as she walked on the dirt path between tents and clothes hanging on trees.

"They sleep under that tent," DeLauro said. "We have created here an unbelievable outrage against humanity."