If AC is 40% black, it’s because they went there for the work, and stayed for welfare on the beach after the gambling became less unique (AC was one of the first alternatives to Nevada). You’re right, it isn’t going to become the Riviera all at once.
Also, the idea of giving AC a “cut” of Northern NJ gambling revenues is a typical central planner’s move of cross-subsidization to patch problems.
AC was more than 40% black pre gambling days.
AC had a large black population BEFORE legalized gambling. When gambling went in, the city actually improved quite a bit - new housing, etc. Many of the casinos just replaced the existing hotels (which were failing).