July 19, 1969 - the first light is shining on Dike Bridge in Chappaquiddick Island, when the brakes of the full-sized Oldsmobile '88 fail to keep it on the asphalt. The car turns abruptly and drives off the right side of the small timber bridge that connects the island with the State of Massachusetts.

The overturned Oldsmobile sinks swiftly in Poucha Pond and Ted has to think fast. A few seconds later he ascends to the surface. Ted is alive. But for Mary Jo Kopechne, the 28-year-old woman who had been sitting next to him, life is no more.

A few years later, in 1972, leading American newspapers and political analysts would say that the accident proved to be a crucial point in Kennedy's political career and maybe American politics.

Ted Kennedy and Kopechne were returning from a party for the "Boiler Room Girls," a group of young women who had worked on Senator Robert F. Kennedy’s 1968 presidential campaign, when Robert’s brother, Ted, possibly under the effect of alcohol, lost control of the car

Now, seated on the shore, he has to think about what to do. He calls Kopechne’s name several times from the shore and attempts to swim down to reach her seven or eight times, but vainly.

If he doesn’t report the incident in a few hours, the authorities will start searching for them - he decides to hide. Ten hours later, after the police have found the body and the car, he surrenders to the authorities.

But it’s too late.

With the Oldsmobile and Kopechne his presidential hopes had also sunk.

Six days after the accident, Kennedy pleaded guilty to leaving the scene of an accident and the court gave him a two-month suspended sentence. Later that night he gave a national broadcast: "I regard as indefensible the fact that I did not report the accident to the police immediately." Kennedy, a married man, denied any kind of immoral conduct with Kopechne and that he had been driving drunk.

In May 1971 Kennedy declared that he would not run for the Democratic Party nomination for the 1972 presidential election, although polls suggested he could win the nomination. "It feels wrong in my gut," he said, adding that he needed "breathing time" to take care of his family. But the newspapers said that Chappaquiddick was the reason for opting out.

Nine years later, Kennedy decided to run. But in 1980, he would have to wrest the nomination from the incumbent president, Democrat Jimmy Carter.

Time Magazine reported on June 25, 1979, that at a White House dinner with legislators, Carter had said, “If Kennedy runs, I'll whip his ass.” A few hours later, Kennedy reportedly roared with laughter when he learned about Carter's crack, joking, “I always knew the White House would stand behind me, but I didn't realize how close they would be.”

Kennedy was now armed with determination and his voters' support. By August 1979, when he decided to run, polls showed him with a 2-to-1 advantage over Carter.

But the eleven years that had passed since the Chappaquiddick incident weren't enough to make people forget it. On March 18, in a key primary in Illinois, Chappaquiddick hurt Kennedy badly among Catholic voters. During a St. Patrick's Day Parade, Kennedy had to wear a bullet-proof vest due to assassination threats, as hecklers yelled "Where's Mary Jo?" at him. Carter crushed Kennedy on polling day, winning 155 of the 169 Illinois delegates. Overall, Kennedy had won 10 states in the race against Carter, who had won 24.

Although Carter won the Democratic Party nomination, write Michael Barone and Richard E. Cohene in the Almanac of American Politics in 2008, his difficulty in securing Kennedy supporters during the general election campaign was one of things that led to his defeat in November by Republican Ronald Reagan.

Kennedy's misfortune at Chappaquiddick had done its job. It held him in its swirl, disarming him of his presidential potential. Without that low point, he would have been the nominee instead of Carter, concluded Paul Boller in his 2004 book on presidential campaigns. Another commentator, James Boughman, came to the same conclusion in his book on the mass media in America since World War II. Both scholars also said that without the accident, Kennedy would probably have beat Reagan, and that he could have beaten Nixon a decade earlier.

In the years that followed, the American and global press added more and more to Kennedy’s negative image. In 1989 Kennedy was pictured by paparazzi having sex in a motorboat. In 1990 Michael Kelly's long, thorough profile appeared under the title “Ted Kennedy on the rocks.” Later, GQ magazine captured him as “an aging Irish boy clutching a bottle and diddling a blonde," keeping his behavior at the forefront of public attention.

Even in 1991, he went out for a drink with his son and nephew and came back home burdened with a rape scandal. The accused was his nephew and although Kennedy was not directly implicated in the case he became the frequent butt of jokes on late-night television shows. The same year, Time magazine said Kennedy was perceived as a "Palm Beach boozer, lout and tabloid grotesque," and Newsweek called him "the living symbol of the family flaws."

Although his private life was different from the ordinary politician’s life, however, Kennedy thrived as a legislator, leaving his mark on issues concerning civil rights, health care, education, voting rights and labor. Up to his death he was chairman of the Senate Committee on Health, Education, Labor and Pensions. With his influence he led Congress to impose sanctions on South Africa over Apartheid, pushed for peace in Northern Ireland, and won a ban on arms sales to the dictatorship in Chile. He was a prominent opponent of the Vietnam War and, in 2002, he voted against authorizing the Iraq war, calling it “the best vote I’ve made in my 44 years in the United States Senate.”

And he was more than a legislator. His voters gave him eight continuous election wins for the Senate with over 55% of the votes. President Barack Obama, who referred to him as a mentor in his eulogy on August 29, 2009, said, “Mr. Kennedy was one of the nation’s greatest senators…. His ideas and ideals are stamped on scores of laws and reflected in millions of lives — in seniors who know new dignity, in families that know new opportunity, in children who know education’s promise, and in all who can pursue their dream in an America that is more equal and more just — including myself.”