Roughly 41 million Americans served in the military during wartime, with about 1.1 million dying in battle, of disease or in accidents. Just under 1 out of every 35 Americans who served during wartime gave their lives in service.

On Memorial Day weekend, we should understand why they died.

The size of the sacrifice is enormous. Nearly all who died were young, perhaps 19 or 20 years old on average. They gave up decades of life, four or five on average, for their service. Using modern estimates of the value of a statistical life, this sacrifice is about $14.3 trillion.

Many things brought American servicemen into uniform. Most were volunteers, and nearly all who were drafted could’ve contrived a way to avoid service by faking a bad cough, mental illness or even bone spurs. Even if they went reluctantly, they went willingly.

Young people are drawn to service for varied reasons. Many believed in the cause for which they fought. Some wanted to leave home, escape a bad job or flee a heartbreak. These reasons explain how a young man or woman might have been pulled into service, but they don’t explain why they died.

From the opening shots of our Revolution at Lexington, Mass., Continental soldiers and sailors swore allegiance to the nation and “against all their enemies opposers whatsoever; and to observe and obey the orders of the Continental Congress and the orders of the Generals and officers set over me by them.”

In 1789, as the Constitution was being ratified by individual states, the oath changed to include this: “I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same.” Over the following 235 years, a full 13 generations, that oath has scarcely changed.

Every one of those 1.1 million war dead swore this oath. It didn’t matter where they fought, the wisdom or error of the conflict. It was this oath that brought them to the battlefield. They died bearing true faith and allegiance to the Constitution.

More than 350,000 died fighting domestic enemies, primarily the Confederacy, and the remaining almost 750,000 died fighting foreign enemies. These ranged from minor affairs, such as the First Sumatran expedition, to the world wars.

Our Constitution remains a radical document that codified a few sweeping ideas. All of us are created equal, and made so not by government, but by a higher power. Those rights mean that we can choose to freely associate, worship and speak openly without fear. The Constitution was written to create a republic with checks and balances and with elected officials responsive to “We the People” through elections. It is for this principle they died.

The goal of the Constitution was to “form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity.” This was radical in 1789 and remains so today.

The founders were men of the Enlightenment, so they knew well that the Republic failed to fully implement the vision of our Constitution. Martin Luther King, Jr. said it most clearly: “When the architects of our republic wrote the magnificent words of the Constitution and the Declaration of Independence, they were signing a promissory note to which every American was to fall heir.”

The men and women who died in our wars made payment on this promissory note of freedom, either by providing for the common defense or securing the blessings of liberty. That is why they died.

Despite this enormous sacrifice, domestic tranquility seems distant. We live in troubled times, made so by many of our fellow citizens who reject the basic tenets of our Constitution. This dishonors the memory of Americans who died in the course of bearing “true faith and allegiance” to our Constitution.

To be clear, I’m not referring to policy disagreements, disputes about separation of powers or judicial theory. Arguments about these matters fall well within our Constitutional order. Indeed, the Constitution was formed to offer us a way to solve these disagreements.

Today the very life of our Republic is at risk by those who reject electoral results they don’t like, reject the view that we are created equal and promise retribution for policy differences.

I am frustrated by decades of silly claims of stolen elections and by petty-minded politicians of both parties. I’m deeply disappointed in the lack of character in so many elected officials and disenchanted by policy gaffes from the war in Iraq, to fiscal stimulus to abortion laws to border security.

I’m mad about inflation, about tariff policies, the price of housing, gas prices, the growing size of government, immigration, homelessness, crime, and healthcare monopolies. I wish that the upcoming election was about these issues, but the 2024 elections are not about policy.

The choice before us is simple. Do we continue our 235 years of Constitutional order, or walk away from it? Today we are faced by a movement that has already attempted to overturn an election, incites violence and openly promises retribution against citizens who oppose them.

In other words, they reject the Constitution. There is nothing more un-American than that, yet many appear on ballots across the nation. It is a stunning turn of events.

Memorial Day can be difficult for many Americans. Some of us feel guilty for having survived combat. Others will miss friends and loved ones who did not. To remember them, we will place flags, say prayers, attend ceremonies or quietly reminisce on our own. I don’t think any of that is sufficient to the challenges of our times.

On this Memorial Day, we must understand that the sacrifice of 1.1 million Americans had deeper meaning. Since that skirmish on Lexington Common 249 years ago, they died giving life to the words of our Constitution. That work is unfinished. It is up to those of us who remain to ensure that the radical ideas of our founding survive and flourish.

We must reject those who would seek to overturn elections, call upon us to hate fellow citizens or provoke political violence. We must reject them at the ballot box and in public life. Anything less dishonors the sacrifice we remember on Memorial Day.