(CNN) Bruce Springsteen went off book at his Broadway show on Sunday night to blast the administration's border policy that has led to the separation of families. Before launching into a performance of "The Ghost of Tom Joad," a song that is not normally part of his setlist, Springsteen called the treatment of immigrant families at the American border "so shockingly and disgracefully inhumane and un-American that it is simply enraging," according to a transcript provided on his official website. But I've also lived long enough to know that arc doesn't bend on its own," he said.