Martin Sheen has been playing iconic leading men for nearly 70 years from "Badlands" to "Apocalypse Now" and of course as President Jed Bartlet in "The West Wing." But the Emmy and Golden Globe winner says that while acting is his profession, activism keeps him alive. The son of immigrants, social justice is at the center of his life; Sheen's decades of non-violent civil disobedience has earned him the dubious distinction of being the most arrested celebrity in Hollywood. At MSNBC's annual live