Even Jerry Lewis admits his unreleased 1970s Holocaust movie is “bad, bad, bad” — no minor fact because the 87-year-old comedian directed, wrote and starred in the film. Now, thanks to some leaked video, people can see how Lewis might have been right.

A seven-minute report from a 1972 Danish television show about the making of “The Day the Clown Cried” surfaced recently, and based on that, the movie looks hammy and self-important at the same time.

Shot more than 40 years ago, the movie stars Lewis, in one of his first serious turns as an actor, as a circus performer arrested by the Gestapo and thrown into a concentration camp. Once there, he starts performing for Jewish children, and reportedly travels with some of them to Auschwitz....