“Chappaquiddick” is a drama based on the 1969 Ted Kennedy scandal, in which the senator and presidential hopeful got into a car accident that left a young woman dead. Driving at night, Kennedy drove his car off an unlit bridge that had no guardrails. The car flipped, and he swam to safety, but 28-year-old Mary Jo Kopechne was trapped inside the car and drowned.

If you’re looking for something to make you feel good about chubby, cherubic Ted, the venerable lion of the Senate, this is not your movie. “Chappaquiddick” is about a young, entitled man, fortified by a coterie of hangers-on and boosted further by family connections, who got away with doing very bad things. It’s a measure of the success of the cover-up that even today, a half century later, the extent of the bad things he did that night remains unknown.

Directed by John Curran, “Chappaquiddick” would probably be more entertaining if it were less responsible, but then it would be less of use as history. We don’t know why exactly Kopechne was in Kennedy’s car. Supposedly, he was driving her to the ferry, but she left her pocketbook and keys at the party. Also, a policeman saw the car parked, and when he got out of his vehicle and walked toward Kennedy’s car, Kennedy pulled away. It seems possible, perhaps likely, though not guaranteed, that there may have been something sexual or at least romantic going on, some party-inspired fling.

It’s also possible that Kennedy was drunk. The movie only goes so far as to note that there was lots of drinking at the party, and Kennedy was no teetotaler. Were he half loaded at the time of the accident, it would make sense that he’d want to wait until his blood alcohol had returned to normal.

This much is certain. The cover-up was grotesque. First the plan was to say that Kennedy wasn’t driving. Then the plan was to say that he was driving and suffered a concussion that prevented him reporting the accident. But wait, lots of people saw him and spoke to him during those hours, and he was hardly disoriented. So the official line was that he was in shock.

Kennedy is played by Jason Clarke, which seems like strange casting, as Clarke often plays heavies. Then you see where the movie is heading and the casting makes sense. The urgency behind the Chappaquiddick cover-up was the desire of the Kennedy family to preserve Ted’s viability as a presidential candidate in 1972. But Ted Kennedy as played by Clarke has no business being president of anything. He’s callow and dishonest, arrogant and a moral coward.

It’s nice he grew to become a better person. But it’s too bad Mary Jo Kopechne didn’t also get the chance to grow with the years. The scene of her death, as played by Kate Mara, as the water slowly rises is the stuff of nightmares.

MOVIE REVIEW

“Chappaquiddick”

Grade: C

Starring Jason Clarke and Kate Mara. Directed by John Curran.

Rated PG-13 for thematic materials, disturbing images, some strong language and historical smoking. Check listings for theaters. 1 hour, 41 minutes.

Bottom line: Fact-based drama that keeps speculation at a minimum