The U.S. Supreme Court case American National Bank & Trust Company of Chicago et al. v. Haroco, Inc., et al., 1984 revolved around the interpretation of the Racketeer Influenced and Corrupt Organizations Act (RICO). The plaintiffs, Haroco Inc., claimed that they were victims of usury by American National Bank through a scheme involving prime rate loans which violated federal law and constituted racketeering activity under RICO. The court had to decide whether a corporation could be both the 'person' who commits the predicate acts constituting racketeering and also be liable as an 'enterprise'. In this case, it was decided that corporations can indeed serve in both roles simultaneously under RICO's civil provisions. Furthermore, it was ruled that no prior criminal conviction is necessary for a private plaintiff to establish standing under civil RICO based on violations of state laws as part of their pattern-of-racketeering-activity allegation.

In the dissenting opinion for American National Bank & Trust Company of Chicago et al. v. Haroco, Inc., et al., Justice William Rehnquist disagreed with the majority's interpretation of RICO (Racketeer Influenced and Corrupt Organizations Act). He argued that to establish a violation under this act, it is necessary to prove an enterprise was operated through a pattern of racketeering activity - not just that there was such activity. The majority’s decision would mean any instance where mail or wire fraud occurred could be considered as racketeering without needing proof that these actions were part of operating an enterprise illegally. This broad interpretation could potentially criminalize regular business activities if they involved some form of deceit but weren't necessarily part of organized crime operations – which RICO was designed to combat against in his view.