The Constitution establishes several limitations on a person’s ability to serve in Congress. For example, Article I, Sections 2 and 3 limit the class of persons eligible to serve in Congress by imposing age, citizenship, and residency requirements. The Incompatibility Clause of Article I, Section 6 imposes a further limitation: it forbids federal executive and judicial officers from simultaneously serving in Congress.

The Framers of the Constitution understood the Incompatibility Clause primarily as an anti-corruption device. Painfully familiar with the system of “royal influence,” whereby the English kings had “purchased” the loyalty of members of Parliament with appointment to lucrative offices, the Framers sought to limit the corrupting effect of patronage and plural office holding in the new Republic. Drawing on examples provided by the bans on plural office holding contained in contemporaneous state constitutions and in the Articles of Confederation, the Framers crafted a ban on dual office holding, which Alexander Hamilton described in The Federalist No. 76 as an important guard “against the danger of executive influence upon the legislative body.”

It is easy, in modern times, to underestimate the importance of the Incompatibility Clause. There has been very little litigation involving its meaning, perhaps because its commands are relatively clear. Yet the clause serves a vital function in the American system of separated powers. By preventing joint legislative and executive office holding, the clause forecloses any possibility of parliamentary government in America, and thus preserves a hallmark of American constitutional government: the independence of the executive and the Congress.

Beyond this vital structural function, what is perhaps most interesting about the clause is what it does not, by its terms, prohibit. Neither the clause itself nor any other constitutional provision expressly prohibits joint service in the federal executive and judiciary, or joint service in federal and state office. The latter issue is largely handled as a matter of state constitutional law, which generally forbids most forms of dual federal–state office holding. As for the question of simultaneous service in federal executive and judicial offices, the constitutionality of the practice might be suggested not only by the lack of a textual prohibition, but by a few prominent examples of such service in the early days of the Republic, such the simultaneous service of Chief Justices John Jay, Oliver Ellsworth, and John Marshall in judicial and executive posts. Nonetheless, examples of joint service in the executive and the judiciary have been rare in American history, and a strong tradition has developed disfavoring the practice. Moreover, some might argue that general separation of powers principles render the practice constitutionally suspect.

What little litigation the clause has generated has centered on two questions: its justiciability and its application to service by Members of Congress in the military reserves. In Schlesinger v. Reservists Committee to Stop the War (1974), the Supreme Court held that citizens who had filed a civil action to challenge the reserve membership of some Members of Congress were asserting only “generalized grievances about the conduct of government” and therefore lacked standing to sue.

Schlesinger did not, however, decide that the Incompatibility Clause could never be enforced in court. Instead, one might read the case to leave open the possibility of judicial enforcement if a sitting Member of Congress who was also an Officer of the United States were to take official action that adversely affected an individualized private interest. On this view, it was only the plaintiff’s lack of a sufficiently concrete and particularized injury that led to the result in Schlesinger.

In United States v. Lane (2006), the U.S. Court of Appeals for the Armed Forces adopted this view. Lane was an appeal of a recusal motion filed by an airman who had been convicted by court martial of a cocaine offense. Senator Lindsay Graham, a lieutenant colonel in the Air Force Reserves, sat on the Air Force Court of Criminal Appeals that reviewed the airman’s conviction. The airman filed a motion to recuse Senator Graham on the ground that his service on the court violated the Incompatibility Clause.

Applying Article III standing principles, the Armed Forces Court of Appeals held that the airman had standing. The court reasoned that the “fact that a Member of Congress sat as a judge in this criminal case” carried “direct liberty implications” for the airman that distinguished his case “from other abstract circumstances where the Incompatibility Clause might be implicated.”

The court in Lane also rejected a theory under which the Incompatibility Clause would always be nonjusticiable, no matter who the plaintiff. On this theory, compliance with the clause is only a condition for service in Congress, not a disqualification from service in the other branches; and enforcement of this condition rests with Congress alone. This was the litigating position of the United States in Schlesinger. Brief of Petitioner, Schlesinger v. Reservists Committee to Stop the War (1974). The Office of Legal Counsel has also endorsed this view. 1 Op. Off. Legal Counsel 242 (1977) (“exclusive responsibility for interpreting and enforcing the Incompatibility Clause rests with Congress”).

Although the United States advanced this “congressional commitment” theory in Lane, the court was not persuaded. The court noted that if the government’s position were accepted, “Members of Congress could serve as the heads of departments and regulatory agencies, simultaneously participating in the passage of legislation and in the execution of the laws” and yet “no citizen could cite the Incompatibility Clause in challenging a governmental decision bearing directly on the life, liberty, or property of the citizen.” In other words, the court believed that leaving the clause to congressional enforcement alone posed too great a risk that the clause would go under-enforced.

On the merits, the court in Lane held that the position of judge on the Air Force Court of Criminal Appeals is an “office of the United States and cannot be filled by a person who simultaneously serves as a Member of Congress.” The Court therefore concluded that the review panel was not properly constituted, invalidated the prior proceedings, and returned the trial record for a new review proceeding.