U.S. Rep. Beto O’Rourke is leading another delegation from Congress to a detention camp in Tornillo to draw attention to the growing population of immigrant children being housed there.

Six months after the El Paso Democrat led a highly publicized Father’s Day tour of the facility, O'Rourke is expected to be joined Saturday morning at the camp by U.S. Rep. Judy Chu, a California Democrat, and Democratic U.S. Sens. Mazie Hirono, of Hawaii, Jeff Merkley, of Oregon, and Tina Smith, of Minnesota.

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Tornillo was expected to initially house 360 children. But the facility is approaching 3,000 childrenin what has become the largest migrant youth shelter in the country just a few hundred yards from the Rio Grande River in far West Texas. Nationwide, the number of immigrant children in government custody is reported to be over 15,000.

O’Rourke lost his campaign against U.S. Sen. Ted Cruz in November. His term in Congress ends in the first week of January.