In the 1945 case Kotteakos et al. v. United States, the U.S Supreme Court ruled in favor of Simon Kotteakos and others who were convicted for conspiracy to defraud the United States under a single indictment involving multiple unrelated conspiracies. The court held that this was not one overall conspiracy but several separate ones, each with its own participants and objectives. Therefore, trying them together as if they were part of a single scheme violated their rights under the Sixth Amendment which guarantees defendants a fair trial by "an impartial jury." This ruling established an important precedent known as “the rule of variance,” stating that there must be sufficient similarity or connection between different acts alleged in an indictment for them to be tried together.

In the dissenting opinion for Kotteakos et al. v. United States, Justice Rutledge argued that the majority's decision to overturn the convictions was incorrect and overly cautious in its interpretation of conspiracy law. He believed that there was sufficient evidence to prove a single overarching conspiracy among all defendants, rather than multiple separate conspiracies as determined by the majority. The fact that some co-conspirators may not have known each other or participated in every aspect of the scheme did not negate their involvement in a common plan orchestrated by Brown, who acted as a hub connecting various spokes (participants). Furthermore, he contended that any error made during trial proceedings was harmless and didn't affect substantial rights of accused individuals since overwhelming proof existed against them individually on substantive charges tied directly with conspiracy accusation.