Even before The Irishman, Scorsese was expressing an interest in the teamsters union, whose pension fund was embroiled in the real-life casino skimming operation that Casino is based on.
Even before The Departed, it proved that Scorsese’s crime schtick could work when transplanted to a different locale from the Five Boroughs – in this case, Las Vegas. Roughly the midpoint of Scorsese’s career, Casino is a film that seems to pull its various elements from a number of other Scorsese movies, while foreshadowing others to come.