television 's make-believe violence rolled on nevertheless , through the sixties , past charles whitman up on the texas tower ( 'there was a rumor/about a tumor , ' kinky friedman and the texas jewboys sang gleefully , 'nestled in the base of his braiyyyyn ... ' ) , and what finally killed it and ushered in the sitcom seventies was a seemingly unimportant event when compared to the deaths of a president , a senator , a great civil rights leader .