On March 4, 2015, the U.S. Supreme Court heard oral argument in King v. Burwell,[1] a tremendously important case involving the administration of the Patient Protection and Affordable Care Act, also known as Obamacare. King is important for a number of reasons. It’s important because a lot of money is at stake.[2] It’s important because it may require fundamental changes to be made to Obamacare.[3] And it’s important—indeed, perhaps it’s most important—because of its significant implications for the rule of law. In this Essay, I explain why the president’s actions in King were unlawful and why a ruling striking down the president’s actions is crucial to ensure the continued vitality of the rule of law.

From the early days of the Republic, a core component of our constitutional character has been the idea that our government is a government of laws and not of men.[4] This means that our leaders—elected and appointed—are constrained by the words in our statute books and in our Constitution.[5] Government officials must follow the law, even when their personal predilections would lead them in a different direction. This prevents arbitrary decision making and keeps executive discretion within proper bounds.