True, there are some places where Mr. Trump does seem likely to have a big impact — most notably, in crippling environmental policy. But that’s what any Republican would have done; climate change denialism and the belief that our air and water are too clean are mainstream positions in the modern G.O.P.

So Trumpist governance in practice so far is turning out to be just Republican governance with (much) worse management. Which brings me back to the original question: Does the appalling character of the man on top matter?

I think it does. The substance of Trump policy may not be that distinctive in practice. But style matters, too, because it shapes the broader political climate. And what Trumpism has brought is a new sense of empowerment to the ugliest aspects of American politics.

By now there’s a whole genre of media portraits of working-class Trump supporters (there are even parody versions). You know what I mean: interviews with down-on-their-luck rural whites who are troubled to learn that all those liberals who warned them that they would be hurt by Trump policies were right, but still support Mr. Trump, because they believe that liberal elites look down on them and think they’re stupid. Hmm.

Anyway, one thing the interviewees often say is that Mr. Trump is honest, that he tells it like is, which may seem odd given how much he lies about almost everything, policy and personal. But what they probably mean is that Mr. Trump gives outright, unapologetic voice to racism, sexism, contempt for “losers” and so on — feelings that have always been an important source of conservative support, but have long been things you weren’t supposed to talk about openly.

In other words, Mr. Trump isn’t an honest man or a stand-up guy, but he is, arguably, less hypocritical about the darker motives underlying his worldview than conventional politicians are.

Hence the affinity for Mr. O’Reilly, and Mr. Trump’s apparent sense that news reports about the TV host’s actions are an indirect attack on him. One way to think about Fox News in general, and Mr. O’Reilly in particular, is that they provide a safe space for people who want an affirmation that their uglier impulses are, in fact, justified and perfectly O.K. And one way to think about the Trump White House is that it’s attempting to expand that safe space to include the nation as a whole.

And the big question about Trumpism — bigger, arguably, than the legislative agenda — is whether unapologetic ugliness is a winning political strategy.