Have YOU read the Constitution lately?

Improbably, the U.S. Constitution has become a runaway bestseller. The reason, of course, is Khizr Khan's speech at the Democratic convention, and in particular these words posed to the Republican presidential nominee: "Let me ask you: Have you even read the United States constitution? I will gladly lend you my copy."

Pointedly, Khan added, "In this document, look for the words 'liberty' and 'equal protection of law.' "

Khan's words have pointed the Constitution's thousands of fresh readers toward a text that might well surprise them. Still, James Madison, father of the founding document, would be pleased.

What many new readers will discover is that Articles I through V emphasize not individual rights, but the structure of government. They specify, in sometimes mind-numbing detail, which branch can do what.

To find the word "liberty," you have to look pretty hard. It appears only three times, and the first mention comes late in the preamble (well after "common defense"). The phrase "equal protection of the laws" appears just once — not in the original Constitution or even the Bill of Rights (the first 10 amendments, added in 1791). It took a Civil War to get them there.

The heart of the Constitution consists of Articles I, II and III, which create the legislative, executive and judicial branches. If you read these articles afresh and without predispositions, you see that the structure protects liberty not by abstract declarations, but by specifying the institutions that safeguard it.

There's a lesson there. Madison himself had little faith in what he disparaged as "parchment barriers." When the Constitution was ratified in 1789, it contained no Bill of Rights at all — and at the time, Madison thought it shouldn't.

At the same time, the president's power is sharply bounded. True, he is made "Commander in Chief of the Army and Navy of the United States." But his is the "executive power" — to implement, not to create, the law. That's central to liberty, because it denies any single person the authority to do whatever he or she wants.

Article III creates an independent judiciary. Judges have life tenure, and Congress cannot cut their salaries, and in that way engage in political reprisal against the federal courts.

The second mention of "liberty" comes in the Bill of Rights, specifically the Fifth Amendment, which forbids the national government from depriving people of "life, liberty, or property, without due process of law." (In the entire Constitution, the word "freedom" appears just once, in the First Amendment's protection of freedom of speech.)

The phrase "equal protection of the laws" doesn't show up until the 14th Amendment, and a modern reader might well wonder: What exactly does that mean? There is a good historical argument that the provision is not a general guarantee of equal treatment, but a narrow requirement that African-Americans, above all the newly freed slaves, would receive the same "protection" as white people. (The Black Lives Matter movement has strong historical roots.)

Those who are reading the Constitution for the first time are bound to be impressed to learn how precisely the structure designed in the late 18th century has persisted until today.

Originally opposed to the Bill of Rights, Madison changed his mind during the year after the Constitution was written. He spoke of how the bill would influence the nation's culture.

In a letter to Thomas Jefferson in 1788, Madison argued that the "political truths declared in that solemn manner" will "become incorporated into the National sentiment," and thus "counteract the impulses of interest and passion." The Bill of Rights, he said, "will be a good ground for an appeal to the sense of the community."

As usual, Madison had extraordinary powers of foresight. Well over 200 years later, Khizr Khan has appealed directly to the sense of American community — and the national sentiment appears to be right there with him.