The military vote was the elephant in the room at NBC’s “Commander in Chief” Forum aboard United States Ship Intrepid. On the morning of the event, NBC released the results of a poll suggesting that among active duty and veterans of the military, The Donald is ahead by 19 percentage points. We’ll see how the polls change, if at all, after Americans digest the broadcast. Our guess is that Mrs. Clinton failed to change the military minds and will lag behind in the military vote all the way to November.

It would be a mistake to make too much of the military vote. One of the bedrock principles of America, after all, is the supremacy of the civilian leadership over our uniformed services. It would also be a mistake, though, to make too little of the military vote. Particularly because Mrs. Clinton has sought to make this election a referendum not on substance but on whether Mr. Trump is “fit” to serve as commander in chief. After all, the Army and Navy (and, in certain circumstances, state militias) are of what he’s commander in chief.

Not only that, but of all the institutions in America, it turns out that our military is the most respected. This is an amazing point for those of us who came of age in the Vietnam generation, in which our military was being spit on after returning from battle against the communists in Southeast Asia. Yet just the other day, no less a figure than the president of Harvard University, Drew Faust, reminded cadets at West Point that the Gallup Poll had recently discovered that “the military is the last institution in which Americans have high confidence.”

“Not organized religion, not government, not newspapers, not banks — you,” President Faust told the cadets. “You and all you represent.” The Editor of the Sun called Mrs. Faust’s remarks a “historic salute,” which is something to keep in mind as Americans reflect on the military vote. As recently as 2004, when the Democrats made the mistake of nominating John Kerry for president, the Swift Boat Veterans for Truth rose up and labeled Mr. Kerry “unfit for command.” Voters responded, and the veterans changed the course of American history.

The Swift Vets were vindicated not only by the fact that the voters bowed to their judgment, but also by Mr. Kerry’s own performance. He withdrew his support for our GIs even though he had voted to send them to a war in which they were still in combat (that’s the business about having voted to resupply our army in Iraq before he voted against it). He emerged, while secretary of state, as a tribune of appeasement. The 2004 election reminded us that our veterans, of all ranks, are wiser on foreign policy than the left gives them credit for being.

Nor is it just foreign policy, either. Presidents and would-be presidents have been watching the military vote since the uprising of the Bonus Army put paid any hopes that President Hoover might have had for a second term. So it’s no small thing that the military vote is breaking against Mrs. Clinton in favor of Mr. Trump. Commander in chief may not be the only assignment of the president of America. But the military vote represents the net assessment of the most respected institution within the federal government.