Whenever she was asked who her greatest influence was, Joan Rivers responded with characteristic quickness, "Lenny Bruce." This shouldn't come as a surprise to those who know her comedy. Bruce spent his entire career overstepping the limits of what could be said on stage. Thrice tried for obscenity, he pushed the latitudes of comic expression far enough to inaugurate a genre that would come to be defined by extreme license -- stand-up comedy. His was comic license in its purest form: if the joke hit, he killed, and his trenchant social critique took no prisoners ; if it missed, he was killed, left entirely vulnerable on stage, naked but for righteous anger.
It was an extremely dangerous performing style and, for Bruce, an unsustainable one. He was hounded by critics to an early grave (with narcotics lending generous help along the way). Rivers, on the other hand, spent the entirety of her long career on this edge.