The following is from the 1990 GQ article titled Ted Kennedy on The Rocks:

Biographers first note obvious public drunkenness in the terrible aftermath of Bobby’s murder. In April 1969, flying back from a congressional trip to inspect the living conditions of poor Indians in Alaska, a hard-drinking [Ted] Kennedy pelted aides and reporters with pillows, ranged up and down the aisles chanting “Es-ki-mo power” and rambled incoherently about Bobby’s assassination, saying, “They’re going to shoot my ass off the way they shot Bobby…”

Three months later, on July 18, came the defining moment of Kennedy’s life, when he drove his Oldsmobile off a bridge on the island of Chappaquiddick, sending young Kennedy staffer Mary Jo Kopechne [pictured] to her death and drowning his chances of ever getting to the White House. This much-explored accident is worth mentioning because the factors surrounding it are the same ones so apparent before and so apparent still in Kennedy’s personal life: a childish belief that the rules of human behavior do not apply to himself, a casual willingness to place himself in a compromising positions with an attractive young woman and, most probably, a reckless use of alcohol.

Kennedy has never told anything close to the whole story of Chappaquiddick, the details of which were covered up by Kennedy associates with the help of compliant local authorities, but he has denied that he was driving drunk, or on his way to an assignation when he turned down the deserted dirt road to Dike Bridge. No writer who has seriously studied the events of the night—and there have been many—has believed him. Leo Damore, whose 1988 book, Senatorial Privilege: The Chappaquiddick Cover-Up, is the most thorough examination of the accident, offers strong evidence that Kennedy was probably drunk behind the wheel and probably on his way to a tryst (not, as he claimed, to the ferry to Martha’s Vineyard).

Indeed, it is otherwise difficult to explain the actions Kennedy himself called “irrational and indefensible and inexcusable and inexplicable”: leaving the party alone with Kopechne and without his driver; failing to notice that the had taken a ninety-degree turn that led down a very bumpy dirt road away from the smooth asphalt road that led to the ferry; never calling the police for help in rescuing the trapped drying Kopechne but relying solely and clandestinely on his two closest aides; and failing to report the accident until after it was discovered ten hours later.

There have been many theories advanced to explain Kennedy’s behavior, all of which make much of the extraordinarily competitive and amoral atmosphere (especially as far as the treatment of women was concerned) in which the Kennedy boys were raised. As Garry Wills makes clear in his elegant The Kennedy Imprisonment, Ted Kennedy was born and bred to act like the last of the Regency rakes: to be a boor when it pleases him, to take what he wants, to treat women as score-markers in the game of sport-fucking and to revel in high-stakes risks. Joseph Kennedy Sr. flaunted his affairs in front of his wife and children, made crude passes at his sons’ dates and well past his middle years was still chasing doxies. John Kennedy’s mad womanizing—frolicking with nudettes in the White House swimming pool, banging a call girl in Lincoln’s bed, carrying on barely secret affairs with admitted mobster girlfriend Judith Campbell Exner, with Marilyn Monroe and Jayne Mansfield—was beyond anything Teddy has ever done or, for that matter, anything anybody has ever done. Neither Joe nor Jack was punished by church, state or wife for such behavior and the late-born Teddy, coming into the family when its adult behavior patterns were already mythologized, presumably figured that neither the rules of decency nor of retribution applied to a Kennedy. The boy grew to manhood without learning how to be an adult. His drinking suggests nothing so much as a frat boy on a toot. His actions with women seem to be more evidence, as writer Suzannah Lessard put it in 1979, of “a severe case of arrested development, a kind of narcissistic intemperance, a huge, babyish ego that must constantly be fed.”