Producer Peter Kunhardt : The film is a co-production between the United States and Germany. Documentary uses archived footage , photos . Two decades later , when it was announced he was diagnosed with brain cancer and that he was coming up on nearly half a century in the Senate , HBO Kunhardt : Kennedy `` never let up '' to carry on where brothers left off .
Producer Peter Kunhardt : The film is a co-production between the United States and Germany. Documentary uses archived footage , photos . Kunhardt : Kennedy `` never let up '' to carry on where brothers left off .