Over the years, I have come to realize that many of my students know little about the U.S. Constitution. And even as I speak to older generations, I realize parts of the Constitution are somewhat foreign to them as well. Most know the basics and major clauses, but there is so much more of our Constitution that is often glossed over.

One such clause that is often considered controversial focuses on privileges, immunities, and debate.

Article I, Section 6, Clause I, Part II states, “They [Congress] shall in all Cases, except Treason, Felony and Breach of the Peace, be privileged from Arrest during their Attendance at the Session of their respective Houses, and in going to and returning from the same; and for any Speech or Debate in either House, they shall not be questioned in any other Place.”

In a nation priding itself that no one is above the law, this clause might seem to go astray.

What is important to understand is that our Founders were protecting the freedom of the legislature, but not the individual members. Yet to protect the one, they had to protect the other. Their fear was that, to hamper legislation, individuals could tie up legislators with litigation, making it impossible to perform their duties.

Justice Joseph Story, who wrote what I consider the best commentary on our Constitution, argued the importance of this clause, claiming that if a representative was taken away from his duties, then the people he represents lose their voice in debate and votes. If a senator is taken away, then the state loses half its power to debate and vote.

This “privilege” only applies to civil cases and not criminal ones as the clause exempts “Treason, Felony and Breach of the Peace.”

In 1908, the U.S. Supreme Court not only agreed with only civil cases, but helped define what was meant by “Treason, Felony and Breach of the Peace” in the case of Williamson v. United States (1908).

In 1905, Congressman John Williamson, D-Oregon, was tried and convicted in his home state for conspiracy to suborn perjury as part of a land fraud scheme.

Williamson claimed privilege under the Constitution. His appeal became the 1908 Supreme Court case in which the Court ruled that “privilege” only applied to civil, not criminal cases. It also went on to claim that the phrase “Treason, Felony and Breach of the Peace” was commonly used by Parliament and the colonies to represent all crimes, and the Founders would have seen it that way. In other words, congressmen were only privileged from civil cases and not from criminal prosecution.

As for the “and for any Speech or Debate in either House, they shall not be questioned in any other Place” clause, this was essential for the separation of powers.

The “any other place” is referencing the other two branches of government.

James Madison wrote in The Federalist Papers No. 48, “It is agreed on all sides, that the powers properly belonging to one of the departments ought not to be directly and completely administered by either of the other departments. It is equally evident that none of them ought to possess, directly or indirectly, an overruling influence over the others, in the administration of their respective powers.” In other words, Congress needs to deliberate freely, without fear that members will later be punished, sued, or prosecuted for what they say or do in debate.

This clause has been interpreted several times by the Supreme Court, but arguably, the most important case was Gravel v. United States (1972).

In 1971, Alaskan Democratic Sen. Mike Gravel received a copy of The Pentagon Papers — a set of several thousands of classified documents concerning U.S. involvement in Vietnam. Wanting to expose the documents, the anti-war senator read portions at a meeting of his Senate subcommittee and placed them on the official record. Afterwards, he arranged for a private publisher (Beacon Press) to publish the full set of documents.

Trying to plug the leak, a federal grand jury subpoenaed Gravel’s aide, Leonard Rodberg, to testify about how the senator got the papers and how publication was arranged. Gravel cited the Speech or Debate Clause, claiming neither he nor his aide could be questioned.

The Court picked up the case, and, in 1972, issued their decision. The Court argued that legislative acts are fully protected including speeches, debates, introducing material into the record, voting, and committee work. It also agreed that the protection extended to aides, as it is impossible for congressmen to function without them. So while reading the papers was privileged, the Court, however, broke from Gravel in that private publication of the papers was not protected as it was not a legislative act, but a political one. The case reaffirmed the separation of powers as Congress must be free to deliberate and communicate without interference from the executive or judiciary branches, however, it also set limits when acting outside their legal duties.

James Finck is a professor of American history at the University of Science and Arts of Oklahoma.