In the 1942 case United States v. Swift & Co., et al., the U.S. Supreme Court ruled that a consent decree, which is an agreement or settlement to resolve a dispute between two parties without admission of guilt, can be modified by courts in light of changes in circumstances and facts. The case involved meat packers who were accused of violating antitrust laws through price-fixing agreements under a previous consent decree from 1920. When new evidence emerged suggesting continued violations, the government sought to modify this original decree to prevent further collusion among these companies. The defendants argued that such modification was not permissible as it would alter their rights established by the initial judgment. The Supreme Court disagreed with them and held that federal courts have broad discretion to modify judgments like consent decrees when there are significant changes in factual conditions or law since its entry - especially if those modifications serve public interest objectives such as enforcing antitrust laws effectively.

In the dissenting opinion for United States v. Swift & Co., it was argued that the Supreme Court overstepped its bounds by modifying a consent decree without proper justification or evidence of changed circumstances. The dissenters believed this action violated principles of finality and respect for judicial decrees, as well as disrupted established business practices based on reliance upon those decrees. They contended that changes in economic conditions or public policy should not be enough to justify modification; instead, there must be unforeseen obstacles preventing compliance with the decree's terms. Furthermore, they disagreed with majority’s view about district court’s power to modify its own judgments indefinitely into future under Rule 60(b) of Federal Rules of Civil Procedure because such interpretation would undermine stability and predictability in legal system.