Their lives were transformed by DACA. Here’s what will happen if it disappears.

A former waiter, born in El Salvador, now writes code for a U.S. Navy contractor. A young man from South Korea is using the money he makes selling pastries to help pay for community college. And a psychology major from Ecuador, who feared she’d be stuck babysitting all her life, now plans to earn a doctorate and move to New York.

They are among nearly 800,000 undocumented immigrants whose lives were transformed by Deferred Action for Childhood Arrivals, the Obama-era federal program that President Donald Trump appears ready to phase out.

Trump – who has criticized the program but expressed admiration for the “Dreamers” who benefit from it – plans to announce Tuesday that his administration will stop renewing DACA work permits, starting in six months, those briefed on the situation say. The six-month delay is aimed at getting Congress to pass legislation that would allow the Dreamers to remain in the country legally, these officials said; they cautioned that the president could change his mind at the last minute.

DACA has opened unprecedented doors for young people who arrived here illegally as children or overstayed their visas. It has become, for much of the nation, a new embodiment of the American Dream.

The initiative shielded young immigrants from deportation and allowed them to get two-year, renewable work permits and drivers licenses and to more easily afford college. It meant opportunities beyond low-wage jobs where no official paperwork is filed, and a chance to climb the ladder and enter the spotlight at work as well as school.

“Taking that away is taking everything from us,” said Renata Aldaz, who is studying psychology at George Mason University and joined other DACA recipients last week for a meeting with Sen. Tim Kaine, D-Va., former running mate to Hillary Clinton, who had vowed to preserve DACA had she been elected.

Without DACA, “I personally will not be able to attend college,” Aldaz, who came to this country when she was 3, told Kaine. “I will lose my job. I will lose having to support my family.”

Critics of DACA say the program is a classic example of presidential overreach that takes jobs from citizens and legal U.S. residents. They warn that Trump will face massive opposition if he doesn’t keep his campaign promise to end it.

“It’s actually about protecting American workers,” said Roy Beck, president of NumbersUSA, which has fought to end DACA since the program was created in 2012. The young immigrants in the program “have a compelling case, but struggling American millennials have a more compelling case.”

But the program’s many defenders say DACA recipients should not be punished for decisions made by their parents, and are making valuable contributions to U.S. society.

Some became high school valedictorians. Others are lawyers, engineers or medical professionals. Hundreds returned to school, because the program required it, and made it easier in some states to seek tuition assistance.

“It helped hundreds of thousands of young people feel as though they belonged,” said Roberto Gonzales, a Harvard education professor who runs the largest study of undocumented youth. “It’s been a huge game-changer for them.”

If Trump phases out the program, or if it is successfully challenged in federal court, those young people will become undocumented again – eventually losing their work permits, jobs and health insurance and, in many states, their driver’s licenses. The job losses alone – about 30,000 a month – would cost the U.S. economy billions of dollars in taxes and retraining, according to estimates by the Center for American Progress and Fwd.us.

Many states with large populations of undocumented immigrants, including California and Texas, already allow them to pay in-state tuition at public colleges – whether they have DACA or not. But those in the program say being allowed to work and drive legally – and being free from the threat of deportation – makes it much more feasible to pursue a college degree.

“I feel like as a country, we would be losing” if DACA was rescinded,” Alexandra Duran, a 21-year-old Salvadoran who is a student at Marymount University, told Kaine last week. “We helped build it, in a sense.”

Ricardo Amaya, a 26-year-old from El Salvador, waited tables for years before obtaining DACA and went to college part time, paying more than triple the cost for classes with the out-of-state tuition rate. Now he pays in-state tuition at George Mason and works at a Manassas, Virginia, technology company, where he has helped develop a dozen computer applications, including for the U.S. Navy, that have been downloaded by 60,000 people.

If Trump ends his permission to work, Amaya said, he’ll have to drop out of school.

“I can only work through DACA,” Amaya said at the roundtable. “This has helped me, getting me out of the shadows, off the ground.”

An army of supporters have rallied to save the program, which has the support of 64 percent of Americans, including 41 percent of Republicans, according to an NBC/Survey Monkey poll released last week.

Thousands marched in the streets in New York, Washington, D.C. and California, and a group has kept 24-hour vigil in front of the White House. Twenty attorneys general, all Democrats, urged Trump to keep the program, even as a smaller group of Republican attorneys general and the Idaho governor threatened to challenge the program in court unless Trump rescinds it. Lawmakers filed bills in Congress to create a permanent way for the Dreamers to stay.

But Congress has been unable to pass such legislation in the past. And even if Trump were to grant DACA recipients a reprieve, officials in his administration have said the program may not survive a court challenge.

The DACA recipients who met with Kaine last week sounded grim as they considered their lives without the program. Among them was Min-Su Kang, the 18-year-old from South Korea who just enrolled at Northern Virginia Community College in Annandale and plans a career in computer science; and Gloria Oduyoye, 25, who was born in England and is finishing up her studies at William & Mary Law School.

They know they have been carefully vetted by the U.S. government, which has their names, photographs, and even fingerprints, and by definition is aware of their undocumented status. They wonder how that data will be used if their deportation relief disappears.

Many have lived here nearly all their lives and are fearful of being forced to return to countries they barely remember.

Across the table from Kaine sat Alejandro Zuñiga, a 19-year-old community college student originally from Bolivia. He wore a tie and aspires to be an aerospace engineer. Now he is afraid of being deported.

“We feel we’re Americans, but the society sometimes doesn’t see us that way,” Zuñiga said, adding that DACA has “given me the opportunity to go to school, to work, and to really get to where my parents wanted me to be.”

“We’re talking about the American Dream,” Zuñiga said. “Our version of the American Dream.”

The Washington Post’s Scott Clement contributed to this report