The most important question Chris Wallace asked Donald Trump last Sunday might have been whether the president could “envision a situation” where he might try to amend the Constitution and serve a third term.

“No,” Trump said. “I think the eight-year limit is a good thing, not a bad thing.”

Eight is enough? Whew!

Ever since John Adams sneaked out of Washington, D.C., to avoid Thomas Jefferson’s inauguration (not a terribly courteous thing to do), the peaceful transfer of power from one president to another has been assumed. Strongmen in other countries tend to find a way to cling to power. In America, we respect the rule of law. Historically speaking, this is astonishing. America is exceptional.

If you don’t believe that, look no further than Russia, where Vladimir Putin is essentially now “president for life.” Or consider the case of China’s Xi Jinping, whose power grab earned plaudits from Trump: “He’s now president for life. President for life. And he’s great,” Trump told a group of applauding Republican donors last spring. “And look, he was able to do that. I think it’s great. Maybe we’ll give that a shot someday.”

This was shtick, but humor can be a safe way to launch a trial balloon—or to inject an idea into the public sphere. The fact that Trump’s audience laughed and applauded his comments is less than desirable.

One potential worry could be that a president could use some sort of national emergency—say a widespread terrorist attack—as a pretext for postponing elections. I’m not suggesting some sort of false-flag operation, but instead that a legitimate national emergency provides an opening. (This wouldn’t be entirely unprecedented. After the 9/11 attacks, then-New York City Mayor Rudy Giuliani tried to extend his term for three months.)

Today, Giuliani advises Trump. The rise of Donald Trump—a president whose authoritarian tendencies are on full display—makes what might otherwise seem like a paranoid concern a little more plausible.

I’m not the only person to have voiced concern. Back in May 2016, Andrew Sullivan wrote an essay sounding a similar alarm. “ Could it be that the Donald has emerged from the populist circuses of pro wrestling and New York City tabloids, via reality television and Twitter, to prove not just Plato but also James Madison right, that democracies ‘have ever been spectacles of turbulence and contention … and have in general been as short in their lives as they have been violent in their deaths?’” Sullivan wrote. “Is he testing democracy’s singular weakness—its susceptibility to the demagogue—by blasting through the firewalls we once had in place to prevent such a person from seizing power? Or am I overreacting?”

Probably, yes. But it’s wiser to overreact than to underreact. Liberal democracy is precious. Even if the odds are slim that the president would try to take a page from Putin and Xi—men, it seems, Trump admires—the stakes demand that we remain vigilant.

For now, it’s probably a good sign that Chris Wallace’s question about a possible third term wasn’t terribly newsworthy. Not only did it not drive coverage, it was barely mentioned. Affirming norms shouldn’t be remarkable. It’s probably even debatable whether Wallace risks creating a permission structure, simply by asking the question. In my opinion, we are better off openly discussing things rather than remaining silent under the guise that it’s better to let a sleeping dog lie.

Part of the problem is that there is a rationale for letting presidents have a third term. I would argue, however, that the potential costs far outweigh the benefits.

A brief history on presidential term limits: George Washington set the precedent for serving just two terms, which lasted until Franklin Roosevelt decided to buck the tradition. He was reelected three times before dying in office. The 22nd amendment, ratified in 1951, officially limits presidents to just two terms.

But not everyone agreed with this limit. Ronald Reagan, whose childhood hero was FDR, opposed the idea. Although he never attempted to use it to run for a third term, then-President Reagan told David Frost, ''I would like to start a movement to eliminate the constitutional amendment that was passed a few years ago that limits a president to two terms. Now I say I wouldn't do that for myself, but for presidents from here on.''

Reagan’s worry was that term limits render a president a lame duck during his second term, thus limiting his influence. Others could reasonably argue that, so long as elections are fair, it is simply undemocratic to deprive the voters of the chance to reelect a president who wants to serve.

But presidential term limits serve as guardrails against demagogues and creeping authoritarianism. These guardrails cannot be erected the moment danger shows up; they must be preserved through the good times so that they are sturdy enough to withstand the bad times. The possibility of a third Trump term should serve as a warning to those who would erode norms and institutions in favor of fetishizing democracy.

Trump, being a presumptuous sort, has always assumed he would serve two terms. While the thought of a second Trump presidential term might be enough to give his political adversaries heartburn, it is the notion of a third term that (to them) would be mortifying.

Besides that, it would only postpone the inevitable Ivanka presidency.