Thousands of immigration hearings have been canceled due to the partial government shutdown, according to a survey, leaving immigrants in legal limbo as they await rescheduled dates that could be as late as 2022. Their cases will be added to a record-high backlog of over 800,000 immigration cases that existed before the shutdown started.

Sui Chung, a Miami-based immigration attorney and former president of the American Immigration Lawyer's Association, conducted a survey of over 15,000 law professionals this week, asking how the government shutdown has impacted their cases. Ninety percent of respondents, who were located across the country, said they've had multiple hearings canceled and a third said those cases were individual hearings -- hearings that would have handed down a final decision on a migrant's immigration status.

"Everyone's on edge," Chung said in a telephone interview with CBS News. "It's mentally, emotionally and financially disruptive to everyone involved."

In Houston, a young Central American man, is among those who have had their court dates indefinitely postponed. The man fled the Northern Triangle after being persecuted, both physically and emotionally, for his sexual orientation, according to his lawyer, Ruby Powers. He came to the United States in early 2017 to seek asylum and has been waiting ever since.

"He was so excited to have court this week, and then it was canceled," Powers said in a telephone interview with CBS News. "He's so frustrated. He can't get work authorization until he's seen before a judge."

His hearing this week was supposed to provide him with a Social Security number so that he can work and get a driver's license. Now, his lawyer said he'll probably need to wait until 2021 or 2022 to go in front of a judge.

His is one of four cases that Powers oversees that has been canceled since the partial government shutdown began on December 22. Since then, the vast majority of immigration courts have been closed nationwide, and all non-detained hearings have been indefinitely postponed. Non-detained immigrants make up about 90 percent of immigration court hearings and their cases run the gamut of migrant-focused legal issues, from final asylum decisions to deportations.

Even court filings have ground to a halt at the courts. Rather than processing those documents, court administrators in Charlotte, North Carolina, for example, have been throwing them into brown cardboard boxes for clerks to deal with once the court opens, said Jeremy McKinney, an immigration attorney who serves clients in North Carolina and South Carolina.

"Often what's in these filings is the most confidential, personal information: police reports detailing horrific crimes against my clients, copies of birth certificates," McKinney told CBS News. "It's just a complete state of confusion."

The shutdown is a major blow to the immigration court system, which prior to the shutdown was already stressed to a point of near dysfunction. As of November 30, the immigration court system had a backlog of more than 800,000 cases -- a 49 percent increase since January 2017, when President Donald Trump took office, according to Syracuse University's Transactional Records Access Clearinghouse (TRAC).

Several Trump administration policies have effectively dumped thousands of previously non-active cases onto the docket, making it difficult to process regular immigration hearings. Between the shutdown and those policies, immigration professionals estimate the backlog could climb to 1.1 million cases.

"The irony is that if they don't have their day in court they can't get deported, so if you want to deport people quickly, this is the exact opposite way to do it," said McKinney, who referred to the courts as a "deporting machine."

In Charlotte's immigration court, where McKinney practices, he estimates 600 to 650 cases have already been canceled, including six of his own -- adding to the court's nearly 16,000-case backlog. McKinney doesn't expect the postponed cases will be

rescheduled until late 2020 at the earliest, but more likely 2021. Charlotte's court is fully booked for 2019 and most of the following year.

During previous shutdowns when the courts were closed, McKinney was able to reschedule within three months.

McKinney will have his first final asylum decision case of the year next week. The case will decide the fate of a Central American woman and her children who fled persecution from MS-13, a notorious gang in the North Triangle. The children were targeted for forced recruitment into the criminal enterprise and the mother was threatened, McKinney said.

"We're prepping for trial. We're assuming it's a go-ahead so that there are no surprises," he said.

The work leading up to a final asylum trial is no small feat. Hours go into proving every fact in an immigrant's case, no matter how small. Obtaining police records from Central America is so difficult that McKinney called it a "miracle." If the asylum case ultimately gets canceled, they'll have to do the work all over again for the next hearing, he said.

"It's not the type of client that you can just go back and charge them for the extra work if this gets postponed," McKinney said. "The people for these cases are the most in need."

There's been little guidance from the courts themselves about the status of the hearings. Not appearing at an immigration hearing is a promise for deportation, making migrants wary when suddenly they're told their hearings are off, McKinney said.

One of his clients showed up at court last week just in case -- despite his appearance being canceled, and despite the four-drive to get there.

"This guy was like, 'Are you kidding me? No way. I'm going.' He was basically saying, 'I don't believe you. This is a set up. I'm going to get arrested,'" McKinney said. "It's drilled into these people that if you miss a hearing, it's over. You're deported."

In Houston, Powers said she hasn't been able to get a good night's sleep since the shutdown, scared that the government may reopen in the middle of the night.

"We're getting nothing from the courts," Powers said. "The advice we get from the is just 'watch the news.'"

The Executive Offive for Immigration Review, an arm of the Department of Justice that oversees all immigration courts, did not respond to calls requesting comment. Calls to the office were sent to voicemail, where a recording said it would not be handling press inquiries due to the government shutdown.