There are many things about Donald Trump’s enduring support that I understand in my gut, like opposition to the stupidest woke ideas, such as defunding the police, or the hunger for a strongman who could stop the winds of change. Many Americans feel like strangers in their own homes, thanks to illegal immigration, rapidly evolving social norms and a job market increasingly unsympathetic to the less educated.

But the thing I don’t understand, and will never understand, and will forever be appalled by, is the laughing.

Every time I watched a clip in which Trump was riffing to the crowd about Liz Cheney or “fake news” reporters being shot, or telling people that Kamala Harris is “a shit vice president,” or when he approved of audience members who referred to Harris as a “ho,” you saw crowds of people surrounding him who were laughing uproariously at his crude and violent language.

The implicit message was that the joke is on us, on the rest of us — liberals or conservatives — who still think you can succeed by adhering to norms and playing by the rules, who still think you can succeed as a politician by inspiring your followers and not by insulting your opponents.

My wife, Ann, who is from a small town in Iowa whose schoolteachers she credits to this day for pounding good fundamentals of English grammar into her, shared with me this Washington Post article from Nov. 20, 2023, because it reflected an Iowa so unlike where she was raised that she couldn’t recognize the place:

“The next day, Trump swooped into Iowa for his own event — where he lobbed insults, made crude references and casually tossed out baseless and false claims designed to belittle his opponents and critics in vicious terms. Children wandered around in shirts and hats with the letters “FJB,” an abbreviation for an obscene jab at President Biden that other merchandise spelled out: ‘F— Biden.’”

The fact that Trump only seems to know how to win by denigrating others, and the fact that so many Americans knew this from his first time in office — and raucously welcomed the sequel — well, that bothers me. Because that kind of mindset and behavior is what leads to a full-blown breakdown in norms, and when the norms go, no laws will protect you. That’s when I get scared. That’s when I feel we’ve passed through some normative membrane into a new and very dark room.

Trump could be so much more successful if he actually extended a hand to his opponents, showed them respect and shared credit. But the fact that his default option is always set on crudity or cruelty first — well, watch out.

Because he is going to discover that the problems we face as a country, from debt to competing with China to adapting to artificial intelligence to absorbing extreme weather, are now so big and hard they can only be fixed together, not by him alone. And mocking half the country is not going to be a strategy for success.

In the end, without a change in his behavior, the joke won’t just be on the rest of us, but on his supporters as well.

Thomas Friedman writes a column for the New York Times.