Below, Steve Sailer references the Nick Hornby movie AN EDUCATION, in which

Peter Sarsgaard plays a Jewish (?) con man, whose scams include renting flats to Jamaican hoodlums in 1960 England in order to violently terrorize old white ladies in the neighborhood into selling their homes, from which he collects 6% as their realtor. It was an incredibly unexpected scene.

In an interview with CinemaBlend, Hornby, born 1957, the son of a railway executive, explained this:

Why did David need to be Jewish? Nick Hornby: First of all, in the memoir, he was. Why I kept him Jewish was that in my childhood, there were memories of discovering that an awful lot of my elders and betters were anti-semitic and racist in various ways. I realized that it had been part of Britain's cultural history at that point. The other thing that interested me was the mention of the name Peter Rachman, which is touched on very very slightly in the movie but who was a kind of big Jewish landlord gangster of the late 50s and early 60s, and whose treatment of his tenants was so despicable that it resulted in a change of the law. We still use the word Rachmannism, Rachmannism being a kind of particularly exploitative landlord. There was this sort of Jewish gangster underclass at the end of the 50s beginning of the 60s that I've never seen on film before.

The film is based on a memoir written by Lynn Barber, who started dating a man called Simon Goldman when she was 16, and he, picking up a Twickenham schoolgirl in his big car, said he was 27. (That's the scene pictured above from the movie.)

Peter Rachman was a landlord who specialized in moving out older white tenants from London properties, and installing West Indian immigrants. In this case, they weren't just "fleeing," they were being pushed. Rachmanism is in the OED, but with one n.

Peter Rachman's Wikipedia entry says that

According to his biographer, Shirley Green, Rachman moved the protected tenants into a smaller concentration of properties or bought them out to minimise the number of tenancies with statutory rent controls. Houses were also subdivided into a number of flats to increase the number of tenancies without rent controls.[8] He then filled the properties with recent immigrants from the West Indies. Rachman's initial reputation, which he sought to promote in the media, was as someone who could help to find and provide accommodation for immigrants. However, in reality he was massively overcharging these West Indian tenants, as they did not have the same protection under the law as had the previous tenants. By 1958 he had largely moved out of slum-landlording into property development, but his former henchmen, including the equally-notorious Michael de Freitas (aka Michael X/Abdul Malik), who created a reputation for himself as a black-power leader, and Johnny Edgecombe, who became a promoter of jazz and blues music, helped to keep him in the limelight.

Aside from his landlordism, an extreme case of what is called "blockbusting" in the United States, Rachman was involved with organized crime, and prostitution, which meant that he was also involved, tangentially, in the Christine Keeler-Profumo scandal. His "henchman" Michael de Freitas was one of the few black people ever convicted for hate speech against whites. He left England, and was hanged for the murder of two people, one of them the white daughter of a British MP.

Rachman was, in fact, a Jewish immigrant from Poland. He was denied actual British citizenship because of his activities, although he couldn't be deported to Cold War Poland. He died of a heart attack at the age of 43.

That's what Hornby meant when he said "There was this sort of Jewish gangster underclass at the end of the 50s beginning of the 60s that I've never seen on film before."

He didn't ask why he'd never seen it on film before. Maybe it's better not to ask.