The United States Constitution lays out the principle of the separation of powers in three simple steps. Article I of the Constitution gives Congress the power to make the laws of the United States. Article II entrusts the President to take care that the laws be faithfully executed, usually through the actions of other executive branch individuals. Article III then charges the federal courts with applying the laws passed by Congress and enforced by the executive branch when deciding cases and ordering remedies. This constitutional structure avoids concentrating excessive power in any one branch—a protection that is lost when all three functions are put in the hands of a single agency.

Thanks to the rise of the administrative state, agencies like the Securities and Exchange Commission are taking over responsibility for all three functions. The agency promulgates extensive regulations that have the force of law, which it then enforces against individual defendants, often in an SEC tribunal, not in an Article III court. This cozy arrangement is now being tested in Lucia v. Securities and Exchange Commission, argued last week before the Supreme Court.