In his first television interview since the election of Joe Biden as the 46th President, former President Barack Obama sits down with "CBS This Morning" co-host Gayle King to discuss the first volume of his memoirs, "A Promised Land." He talks about the enormous opposition he experienced as he entered the White House; the impact of his political career on his family; and why he campaigned for his former vice president – and spoke out so vociferously against his successor, President Donald Trump.