This is 99% Invisible. I'm Roman Mars. This week, Donald Trump returns to the White House,

and he's promised on day one to begin carrying out the largest domestic deportation operation

in American history. Trump plans to mobilize federal and local law enforcement to remove

millions of undocumented immigrants from the country.

But already, he's facing pushback from cities and states across the country that have declared

themselves sanctuaries and say they won't cooperate.

This is a fight we've had many times before.

And back in 2017, during Trump's first term, we aired a two-part series exploring the

origins of the sanctuary movement. We thought this would be a good week to revisit that story.

Here it is.

In July 1980, a group of Salvadoran migrants crossed the border from Mexico into Arizona.

They walked over an isolated mountain range and halfway across a wide desert valley.

There were more than two dozen of them, people who'd left behind lives and jobs to come to the United

States.

They'd hired some guides to lead them on the journey.

Reporting our story this week is

Delaney Hall. And those guides had brought them to a largely uninhabited part of the border. It was a

vast, empty, and fatally hot stretch of the Sonoran Desert. The temperature the next day got up to

around 112, 115 degrees out there, was deadly.

This is John Fife. He's a Presbyterian minister from Tucson, which is a couple of hours

from where the migrants crossed.

They were in the middle of the most desolate and deadly area of the desert.

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