Mel Baggs, a disabled writer and artist who became an influential champion of a powerful idea — ‘‘that all people are valuable’’ — through candid blog posts and videos that brought them to the fore of ...

When Amelia “Mel” Baggs’ parents took young Mel on a hike years ago in a California forest, the child stopped them and pointed at one of the trees. “She said, ‘There’s something wrong with that tree,' ...