Why do people in Massachusetts have such low standards?

In 1969, Ted Kennedy is partying with his cousin Joe and some friends and some women who had worked on Bobby's Presidential campaign in a cabin on Martha's Vineyard. Despite having a few drinks, Kennedy is driving his car with Mary Jo Kopechne as a passenger. He drives the car off a bridge and the car flips over. He gets out alive, but Mary Jo is trapped in the car.

Instead of calling 911, Kennedy goes back to the cabin and tells his cousin Joe and another friend (who happens to be an A-USA). They go back to the submerged car but are unable to get the doors open to get Mary Jo out. Joe tells Kennedy that he has to call the police and report the accident. Kennedy says he will but goes back to his motel and goes to bed without calling the police.

The next morning, a man and his son walking by the bridge see the submerged car and call the Sheriff. The Sheriff calls a diver to help check if anyone is in the car and if so, to get them out. The driver finds Mary Jo's body in the car and gets her out. The diver says she was trying to keep her face above the water and probably was alive for about 25 minutes after the car went under and he could've gotten her out if someone had called him immediately.

Kennedy's cousin Joe and his A-USA friend went by the bridge and saw the Sheriff there so they went to find Kennedy. Kennedy was having breakfast at the motel with some friends. When Joe and the A-USA asked to speak to Kennedy in private, Kennedy says they just sat down and were about to have breakfast. But Joe and the A-USA insist on speaking to Kennedy in private. So when they're alone, Kennedy tells them he didn't call the police.

Joe and the A-USA convince Kennedy to report the accident to the police. So Kennedy goes to the Sheriff's office, but the Sheriff is at the bridge. The Sheriff's secretary calls the Sheriff and the Sheriff says he'll go back to the office. While waiting for the Sheriff, Kennedy calls Mary Jo's parents and tells them Mary Jo was in an accident. I'm not sure if the phone conversation in the movie was exactly the same as the real conversation that day, but in the movie, not once during that phone conversation did Kennedy ever say to Mary Jo's parents "I'm sorry for your loss".

After the Sheriff gets beck to his office, Kennedy gives him a written statement of the accident. Then Kennedy goes back to the Kennedy Compound in Hyannisport. When he gets back to the Kennedy Compound, there are about a dozen political advisors there ready to put their spin on the events and make sure Kennedy's career isn't jeopardized. Kennedy tries to leak a false story to the newspaper that he didn't report the accident immediately because he had a concussion. Kennedy also shows up at Mary Jo's funeral wearing a fake neck brace.

Kennedy eventually pleas guilty to leaving the scene of an accident and is given a suspended sentence. The movie ends with Kennedy giving a televised speech to the people of Massachusetts, with the goal of trying to spin the events so he could keep his Senate seat. The movie said Kennedy was re-elected overwhelmingly by the people of Massachusetts.

Kennedy was an asshole who lied and did everything he could to try to distort the truth and cover up the facts in a deadly accident that cost a young woman her life. And yet, the people of Massachusetts still re-elected him overwhelmingly.