Marin County supervisors are joining an effort to block a planned ICE holding facility in Santa Clara County, but they disappointed immigrant rights activists who packed a board meeting last week to demand they do more.

Last Tuesday, supervisors agreed to file a friend-of-the-court brief supporting a lawsuit that seeks to halt the development of an ICE holding center near Gilroy—part of the Trump administration’s campaign to add 100,000 beds nationwide. The suit was brought…