` ` Top Ten '' host Johnny Carson opens up 9/11 , politics , fatherhood and more . Three years later , in 1978 , Letterman appeared on `` The Tonight Show . '' He said David Letterman inspired his career , calling his friendship `` a tremendous blessing '' Letterman on ` ` Late Show '' origin : ` ` It was a cheap , easy way to refill a category and get some laughs '' Letterman on politics : `` For the record , I am a registered independent . ''
` ` Top Ten '' host Johnny Carson opens up 9/11 , politics , fatherhood and more . He said David Letterman inspired his career , calling his friendship `` a tremendous blessing '' Letterman on ` ` Late Show '' origin : `` It was a cheap , easy way to refill a category and get some laughs '' Letterman on politics : `` For the record , I am a registered independent . ''