In 2013, Jason Green left his position at the White House—a position he had worked most of his life to obtain—to sit with his terminally ill grandmother and be an audience for the stories she knew about their family and the community they all grew up in.

If you stop the description there, it may sound quaint and commendable. But what he learned was that the person he thought of as “Sweet Grandma Green” was a community organizer—and a bit of a radical—who helped merge three churches, two white and one Black, shortly after the assassination of Martin Luther King, Jr.

Jason thought he would be the family archivist. Instead, he became convinced that the ordinary people he loved and grew up with had something urgent to teach us about the unfinished work of American democracy.

His new book is Too Precious to Lose: A Memoir of Family,  ...