A look at the turns JFK's legacy has taken since his death, and at how his and brother Robert's ghosts have haunted both Republican and Democratic successors. Henggeler (History/Univ. of Texas, Pan American) expands here on his first book, In His Steps (1991), a study of the Kennedy mystique's effect on LBJ. Despite a mixed record as congressman and president, JFK soon came to signify an idealistic promise his successors couldn't hope to match, the author contends. His legacy has been pernicious, derailing three presidents and influencing every presidential campaign since Kennedy's death. Johnson suffered most--overshadowed despite his brilliant legislative accomplishments, vainly trying to appropriate the Kennedy energy and media adulation, eventually brought down by a military entanglement that his predecessor initiated. The presidents and presidential and vice-presidential aspirants who followed have genuflected before the Kennedy image while using the assassinated president for their own ends, but they've often misfired. Hengeller's account leaves us with comic, jarring images: a homely Johnson posing for GQ at his Texas ranch; a staged photo op with Nixon running on the beach--in hard shoes--while reporters mock him; Clinton's JFK handshake replayed, backwards and in slow motion, to enhance its effect on voters. We get hopefuls like Gary Hart being overly Kennedy-esque; Dan Quayle comparing himself to JFK, to the derision of Lloyd Bentsen; and an all-too-human Ted out-Kennedy-ed by the more virtuous Jimmy Carter in 1979. Reservations: Hengeller's lack of respect for Hart and Michael Dukakis is poorly concealed; he runs hot, then cold on Clinton, hedging his bets; and he never satisfactorily identifies the reasons for the role Kennedy plays in public memory. Nonetheless, this meticulous and well-rendered treatise draws history onto important ground--tracking the influence of a single, powerful symbol in an age when political power came to reside increasingly in media spectacle.