On July 25, 1969, Kennedy pleaded guilty to leaving the scene of an accident and was given a suspended sentence of two months. That night, he gave a statement on national television in which he said, "I regard as indefensible the fact that I did not report the accident to the police immediately." Kennedy denied driving under the influence of alcohol and denied any immoral conduct between him and Kopechne. Kennedy asked the Massachusetts electorate whether he should stay in office or resign. He claimed that he received a favorable response in messages sent to him, and apparently it didn't matter to Massachusetts voters because Kennedy was re-elected the following year with 64% of the vote, and re-elected in all subsequent elections until his death in office.
Following is a YouTube video of part of Kennedy's statement:
Just a year previously, at the 1968 Democratic National Convention in August, Chicago Mayor Richard J. Daley and some other party factions did not think that Vice-President Hubert Humphrey could not unite the party, and they encouraged Ted Kennedy to make himself available for a draft. Then 36 years old, Kennedy was seen as the heir to his brothers' legacy and "Draft Ted" movements sprang up among delegates. After testing the political winds and getting a negative reaction from Southern delegates, Kennedy rejected any move to place his name before the convention as a candidate for the nomination. He also declined consideration for the vice-presidential spot.
Chappaquiddick had greatly damaged Kennedy's future presidential prospects. Shortly after the incident, he told reporters that he would not be a candidate in the 1972 U.S. presidential election. In 1971 when some polls suggested he could win the nomination if he tried, Kennedy gave some more thought to running. In May of that year he decided not to run. In November 1971, a Gallup Poll still had him in first place in the Democratic nomination race with 28 percent. When George McGovern was close to clinching the Democratic nomination in June 1972, various anti-McGovern forces tried to get Kennedy to enter the contest at the last minute, but he declined. At the 1972 Democratic National Convention McGovern repeatedly tried to recruit Kennedy as his vice presidential running mate, without success. When McGovern's choice of Thomas Eagleton stepped down soon after the convention, McGovern again tried to get Kennedy to take the nod, again without success. McGovern instead chose Kennedy's brother-in-law Sargent Shriver.
Kennedy finally ran for the Democratic nomination in the 1980 presidential election by running against the incumbent Democratic President Jimmy Carter. A midsummer 1978 poll had shown Democrats preferring Kennedy over Carter by a 5-to-3 margin. Carter was not intimidated despite his 28 percent approval rating, saying publicly: "If Kennedy runs, I'll whip his ass." Labor unions urged Kennedy to run, as did some Democratic party officials who feared that Carter's unpopularity would lead to bad losses in the 1980 congressional elections. In August 1979, when Kennedy decided to run, polls showed him with a 2-to-1 advantage over Carter, and Carter's approval rating slipped to 19 percent.
Kennedy formally announced his campaign on November 7, 1979, at Boston's Faneuil Hall. He received negative press from a rambling response to the question "Why do you want to be President?" during an interview with Roger Mudd of CBS News. The Iranian hostage crisis, which began on November 4, and the Soviet invasion of Afghanistan, which began on December 27, caused the electorate to rally around the president, allowed Carter to pursue a strategy of staying at the White House.
Kennedy's campaign staff was disorganized and the Chappaquiddick incident became a more significant factor than expected. Several newspaper columnists and editorials criticizing Kennedy's answers on the matter. In the January 1980 Iowa caucuses, Carter demolished Kennedy by a 59–31 percent margin. Kennedy's fundraising dropped off and his campaign had to downsize, but he remained defiant, saying "Now we'll see who is going to whip whose what." Kennedy lost three New England contests. Continued concern about Chappaquiddick and Kennedy's personal character prevented him from gaining support of many people who were disillusioned with Carter. In a St. Patrick's Day Parade in Chicago, Kennedy had to wear a bullet-proof vest due to assassination threats as hecklers yelled "Where's Mary Jo?"
Carter ran ads that by implication criticized Kennedy on Chappaquiddick, but Kennedy still managed a narrow win in the April 22 Pennsylvania primary. Carter won 11 of 12 primaries held in May, while on the June 3 Super Tuesday primaries, Kennedy won California, New Jersey, and three smaller states out of eight contests. Overall, Kennedy had won 10 presidential primaries against Carter, who won 24. Although Carter had enough delegates to clinch the nomination, Kennedy carried his campaign on to the 1980 Democratic National Convention in August in New York.
On the second night of the convention, August 12, Kennedy delivered what was probably the most famous speech of his career. He concluded with these words:
For me, a few hours ago, this campaign came to an end. For all those whose cares have been our concern, the work goes on, the cause endures, the hope still lives, and the dream shall never die.
The Madison Square Garden audience reacted with wild applause and demonstrations for half an hour. On the final night of the convention, Kennedy arrived after Carter's acceptance speech, and while he shook Carter's hand, he failed to raise Carter's arm in the traditional show of party unity. Carter's difficulty in securing Kennedy supporters during the general election campaign was seen as one of many reasons for his defeat in November of 1980 to Ronald Reagan.