Only on the "CBS This Morning" podcast, filmmaker Peter Kunhardt and writer Trey Ellis join CBS News correspondent DeMarco Morgan to examine Rev. Dr. Martin Luther King, Jr’s final years. Kunhardt and Ellis discuss how in their new HBO documentary “King In The Wilderness, ” King’s closest friends share how he suffered from depression and was nearing a nervous breakdown. From the passage of the Voting Rights Act in 1965 to his assassination in 1968 King saw his popularity diminish has his drive for equality spread to the North and he came out in opposition to the Vietnam War.