BEFORE DAWN on Saturday morning, Aldo Martinez, a paramedic in Fort Myers, Fla., responded with his ambulance crew to a man who, having just been diagnosed with covid-19, was having a panic attack. The man didn’t know that Mr. Martinez, 26 years old, is an undocumented immigrant; nor that he is a “dreamer”; nor that his temporary work permit under an Obama-era program has been targeted by President Trump.

The covid-19 patient was not aware that Mr. Martinez’s ability to remain in the United States, as he has since his parents brought him here from Mexico at age 12, now hangs in the balance as the Supreme Court weighs the future of Deferred Action for Childhood Arrivals, the program known as DACA. What the man did know was that Mr. Martinez, calm and competent, spent 45 minutes helping to soothe him, explaining the risks and symptoms and how to manage them.

Some 27,000 dreamers are health-care workers; some, like Mr. Martinez, are on the front lines, grappling with a deadly pandemic. They are doctors, nurses, intensive care unit staff and EMTs trained to respond quickly to accidents, traumas and an array of other urgent medical needs.

Until now, because of DACA, they have been shielded from deportation and allowed to work legally. Their time may be running out.

The Supreme Court heard oral arguments in the fall on the Trump administration’s attempt to rescind the program; it is expected to rule in the coming months. If, as appears likely, the court’s conservative majority sides with the administration, Mr. Martinez and thousands of other health-care workers would lose their work permits and jobs, and face the threat of deportation. So would another 700,000 DACA recipients — food prep workers, teachers and tutors, government employees, and students, including those enrolled in medical programs.

That would be catastrophic, and not just for the dreamers themselves, young people in their 20s and 30s who have grown up here. It would also be catastrophic for the United States.

Mr. Trump could halt the threat to dreamers with the stroke of a pen, by issuing an executive order. He has referred to DACA recipients as “some absolutely incredible kids” and promised that they “shouldn’t be very worried” owing to his “big heart.” But, so far, he has taken every possible step to chase them out, and his administration has made clear that if it prevails in the Supreme Court, dreamers will be subject to deportation.

That would give Mr. Martinez about four months. His current DACA status expires Aug. 5, and it would probably not be renewable if the administration prevails.

“I don’t want people thanking me because I expose myself to covid — I’m not here for the glamour of it,” Mr. Martinez told us. “The principle is when people are having an emergency, they don’t have safety or security — you’re there to provide that for them in a time of need.”

Now it’s a time of need for Mr. Martinez himself, and hundreds of thousands of other dreamers like him. The country needs them as never before. Will Mr. Trump step up to provide them with safety and security?

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