With this past President’s Day, there were a few programs on radio and television about the presidency and role of various presidents in our nation’s history. One program I happened upon was “On the Media,” a weekly mainstay of National Public Radio (NPR). The segment of the program that caught my attention was focused on the “norms” in the institutions of our government.

By “norms,” we’re not talking about parts of any law or rule that have been passed or adopted in any official way. What we’re talking about are customs—the practices and traditions that have always been observed and that we’ve taken for granted because “it’s always been done that way.”

An example from our nation’s history is the idea that a president serves no more than two terms. From George Washington up to the 31st president Herbert Hoover, presidents served only two terms in office. This wasn’t part of any law, it was simply the custom set down by George Washington and it was observed by all who came after him until Franklin Delano Roosevelt decided to run for a third term in 1940 and then a fourth term in 1944.

FDR felt like he had good reason for breaking with the two-term precedent, including the lingering effects of the Great Depression and the outbreak of war in Europe. Despite this, in 1940 after FDR finally made his intentions known about a third term, there was much pushback and outright anger from various quarters. Keep in mind that FDR wasn’t breaking any law at the time, just historical “norms.” In response, Congress in 1947 approved the 22nd amendment to the Constitution limiting a president to two terms.

In this case, a constitutional amendment was needed because norms and customs were disregarded or set aside. But there are just as many instances in today’s world where we think past customs and norms will serve a “checks and balances” role only to find that these are not up to the job.

For example, there is this idea that the Justice Department, headed by the Attorney General, is above partisan politics and independent from the White House. There is no law stating this and there is nothing codified anywhere to insist on this independence, but over the last several decades, at least since Watergate, this separateness and independence was the norm and the custom.

That norm was shattered very recently when the president voiced his criticisms, while at roughly the same time senior officials at the Justice Department overruled career federal prosecutors to recommend a lighter sentence for Roger Stone, a longtime friend of the president, who was convicted of obstructing justice in the Russia mess.

The reality is that as distasteful and potentially conflict-ridden as some may find it, this intervention didn’t break any laws or violate any statutes—only norms and customs. The same holds true for a presidential candidate releasing his or her tax returns; for many years it was done and expected, but there’s no law or statute requiring that candidates do so. Also, norms suggest using presidential pardons to correct miscarriages of justice for common folk as opposed to shielding cronies, but no law requires this.

We are a nation of laws, but we’re equally a nation of norms, customs, and precedents. If we all agree to follow the unwritten stuff, the thing we call democracy works well. But when the unwritten stuff is disregarded, we find out just how vulnerable and fragile we are.

Many would argue that we’re already overregulated with statutes and far too much government. But I fear that regulation is all that’s left for us if we’ve gotten to the point where we’re unwilling to submit to the practices developed and handed down over the generations of the republic.

Maybe that’s what this next election is about—not so much where candidates stand on particular issues, but whether he or she possesses an understanding of how vulnerable our government institutions can become when historical norms are disregarded for short-term considerations.