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In the year since the Trump administration has ramped up its mass-deportation campaign, members of Congress have attempted various things to rein in ICE or conduct oversight, often to little avail. The number of people in Immigration and Customs Enforcement detention has increased by over 75 percent in just one year, hitting a record 73,000 in mid-January.

House Rep. Joaquin Castro, meanwhile, has set to work quietly attempting to spring people from those cages. And he’s been more effective than most.

Castro has become a regular at the Dilley Immigration Processing Center, a notorious family detention center in South Texas that was closed by the Biden administration after years of scandal and subsequently reopened by the Trump administration. Most recently, Castro helped release the “mariachi teens,” the teenage-brother mariachi stars who visited the White House last summer and were released from ICE detention just a few days ago. He greeted them and the rest of their family at the center as they walked out.

The children and families at Dilley are often held under excruciating conditions, but their numbers are declining: Since Castro’s first trip, in January, the population at the center has dropped from 1,100 to just 450. I called Castro to understand what’s been effective about his efforts. This interview has been edited for clarity.

Alexander Sammon: When you heard that Dilley was going to be reopened, what was your reaction?

Joaquin Castro: Obviously I........

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