President Richard Nixon considered Ted Kennedy such a threat that he tried to catch Kennedy cheating on his wife, even ordering aides to recruit Secret Service agents to spill secrets on the senator's behavior.

''Do you have anybody in the Secret Service that you can get to?'' Nixon asked his aide John Ehrlichman in a stark series of Oval Office conversations about Kennedy before the 1972 election. ''Yeah, yeah,'' Ehrlichman replied.

''Plant one,'' Nixon said. ''Plant two guys on him. This could be very useful.''

Nixon made clear that the Secret Service protection afforded Kennedy before the 1972 election would be rescinded after. Then, said the president, ''If he gets shot, it's too damn bad.'' His aides disdainfully referred to Kennedy supporters as ''super swinger jet set types.''