Sorensen was devastated by Kennedy 's assassination , which he termed " the most deeply traumatic experience of my life . ... I had never considered a future without him . " He later quoted a poem that he said summed up how he felt : " How could you leave us , how could you die ? We are sheep without a shepherd when the snow shuts out the sky . " He submitted a letter of resignation to President Johnson the day after the assassination but was persuaded to stay through the transition . Sorensen drafted Johnson 's first address to Congress as well as the 1964 State of the Union . He officially resigned February 29 , 1964 , and was the first member of the Kennedy Administration to do so
Kennedy 's assassination
Assassination of John F. Kennedy
Ted Sorensen