In the case of Christine Todd Whitman, Administrator of Environmental Protection Agency (EPA), et al. v. American Trucking Associations, Inc., et al., 2000, the Supreme Court ruled in favor of the EPA. The court held that it was not unconstitutional for Congress to delegate authority to the EPA to set air quality standards under the Clean Air Act without a clear and precise directive on how those standards should be determined or what they should be. The trucking associations argued that this delegation was an abdication of legislative power by Congress and thus violated separation-of-powers principles; however, their argument was rejected by both lower courts and ultimately by the Supreme Court as well. Furthermore, while acknowledging economic considerations could play a role in implementing these standards once established, Justice Scalia writing for unanimous court clarified that such factors were not relevant when setting them.

In the dissenting opinion for Whitman v. American Trucking Associations, Inc., Justice Stevens argued that the Environmental Protection Agency (EPA) should be allowed to consider costs when setting air quality standards. He believed that the Clean Air Act's requirement for "adequate margins of safety" implicitly allows cost considerations because ensuring safety often involves balancing risks and benefits, which inherently includes considering costs. Furthermore, he pointed out that other parts of the Act explicitly require cost-benefit analysis or similar economic considerations, suggesting a general legislative intent to allow such factors in decision-making under this law. Therefore, he disagreed with the majority's interpretation excluding cost from consideration in setting these standards.