The Clean Air Act gives the U.S. Environmental Protection Agency (EPA) broad authority to issue regulations aimed at reducing air pollution. Exercising that authority, the EPA issued a rule in 2015 called the Clean Power Plan, designed to limit carbon dioxide emissions from coal-fired power plants. That rule was challenged in court and never implemented. In 2019, the EPA purported to replace it with a new rule, claiming that the original rule was not authorized by Clean Air Act. That decision was also challenged in court. In January 2021, the U.S. Court of Appeals for the D.C. Circuit ruled that the EPA’s justification for rescinding the Clean Power Plan was wrong—that the Clean Air Act indeed gave the agency the authority to issue the rule. The Supreme Court agreed to review this decision, consolidating into one case the various challenges that had been brought against the EPA’s actions.

In their briefing at the Supreme Court, the parties challenging the Clean Power Plan relied heavily on an interpretive presumption sometimes called the “major questions” rule. According to the challengers, laws passed by Congress must speak “with unmissable clarity” before authorizing an agency to address matters with major political or economic significance. Applying that rule, the challengers argued that the Clean Power Plan was legitimate only if the Clean Air Act specifically authorized the precise methods of reducing carbon dioxide emissions that the rule prescribed. The challengers further claimed that the Supreme Court must apply this “major questions” rule as a way of enforcing a constitutional prohibition on laws that delegate legislative authority to agencies—the so-called “nondelegation doctrine.”

CAC filed an amicus brief supporting the EPA on behalf of Julian Davis Mortenson, a professor at the University of Michigan Law School and a leading scholar on constitutional history relating to legislative delegations of authority. Our brief explained that under the original understanding of the Constitution, there is no prohibition on legislative delegations to enforce, either directly or through a “major questions” rule.

As the brief explained, at the time of the Founding, legislative authority was understood to be inherently delegable. The British Parliament and other legislatures across the Anglo-American world had a long tradition of delegating broad discretionary rulemaking authority to agents, who were not regarded as impermissibly “making law” when they exercised that authority. Consistent with theory and precedent, legislative delegations were a pervasive feature of state governance in America, both before and after Independence.

As we further explained, the ratification of the Constitution did not introduce new restrictions on delegation. Although the Constitution divides power among three branches and assigns all “legislative powers” to Congress, nothing about that division limits Congress’s power to delegate rulemaking authority to executive agencies, so long as Congress retains ultimate control over the legislative process. Furthermore, the debates surrounding the Constitution’s drafting and ratification betray no concern about this type of legislative delegation.

This interpretation is confirmed by political practice in the nation’s first decade, which the Supreme Court regards as weighty evidence of the Constitution’s original meaning. In statute after statute, Congress approved sweeping delegations of policymaking authority over the most crucial issues facing the young nation, among them foreign commerce, patent rights, taxation, pensions, refinancing the national debt, regulating the federal territories, raising armies, and calling up the militia. These delegations routinely granted vast discretion to resolve major policy questions with little or no guidance. In short, delegating broad authority to the executive branch was not rare in the nation’s early history—it was routine.

To explain away the powerful evidence of early congressional enactments, proponents of a strict nondelegation doctrine have devised various artificial limiting principles: Congress may delegate questions involving government operations but not private conduct, powers that “overlap” with the president’s but not “core” legislative powers, the authority to “fill in the details” but not to resolve “important” subjects. These distinctions, as we showed, are entirely a modern invention. No one articulated them in the Founding era. Nor did anyone invoke them to justify early congressional delegations. On the contrary, the historical record refutes the claim that these distinctions mattered to the Founders when it came to legislative delegations.

The Constitution’s original meaning, in sum, provides no basis for a strict nondelegation doctrine or its enforcement through a “major questions” rule.

In June 2022, a 6-3 majority of the Supreme Court held that the Clean Power Plan exceeded the EPA’s authority under the Clean Air Act. While acknowledging that the Act can be read as authorizing the EPA’s plan, the majority invoked the “major questions” rule and concluded that the plan could be upheld only if Congress explicitly prescribed in detail the type of emissions-reducing policies that the plan relied on. This method of interpreting statutes raises the bar on what Congress must say before the Court will allow it to confer power on agencies. To justify its new approach, the majority cited the separation of powers but did not rely on any supposed constitutional prohibition against delegating legislative authority to agencies. In dissent, Justice Kagan echoed our brief in explaining that Congress has used general statutory language to give significant authority to agencies since the Founding.