The Democratic line on Donald Trump is beginning to sound — bear with me on this — a little like arguments made for continued government funding of public broadcasting. One the one hand, we’re told, public money makes up only a small part of the Public Broadcasting Service’s budget. On the other, cutting that allegedly small amount would do irreparable harm to American civilization. You understand what’s meant by these arguments, but you want to say, “Well, which is it?”

Hillary Clinton’s general-election campaign hasn’t begun in earnest, but I wonder if I’m wrong in seeing a similar sort of contradiction at its heart. On the one hand, Trump is fundamentally a liar; he doesn’t take his own words seriously, and neither should you. On the other, Trump is exactly the bully and churl he presents himself to be; what you see in Trump is what you’ll get.

So for instance, Sen. Tim Kaine, Clinton’s vice-presidential running mate, based his convention address largely on Trump’s untrustworthiness, holding up for special derision (by means of an impersonation universally regarded as badly done) Trump’s tendency to accompany his most preposterous claims with the words “believe me” — “It’s going to be great, believe me. We are going to build a wall and make Mexico pay for it, believe me,” and so on. “Well, his creditors, his contractors, his laid-off employees, and his ripped-off students did just that, and they all got hurt. Folks, you cannot believe one word that comes out of Donald Trump’s mouth.” Whereupon his audience took up the chant, “Not one word!”

That Trump can’t be trusted or that he doesn’t mean anything he says was a theme dwelt on by, I estimate, every third speaker at the Democratic convention. The allegation didn’t work on Bill Clinton in 1992, not so much because it wasn’t credible but because the circumstances weren’t right for it. But perhaps Democrats are sufficiently confident in the shape of today’s economy to make the argument about their opponent’s character.

Is it wise, though, for his foes to suggest that Trump doesn’t quite mean some of his most improbable claims? An uncommitted voter might reasonably claim that, well, maybe he won’t actually build a wall, but he’ll do something about illegal immigration, whereas there is little reason to suspect Clinton feels strongly about the issue at all. Or maybe he won’t actually crush the Islamic State just like that – snap – but at least one discerns a hardened and aggressive disposition.

Trump isn’t just untrustworthy, though, according to Democratic portrayals. He’s also utterly real — a bona fide scoundrel, but bona fide all the same. Hillary Clinton herself took this line during her acceptance speech Thursday night. “For the past year,” she said, “many people made the mistake of laughing off Donald Trump’s comments — excusing him as an entertainer just putting on a show. They think he couldn’t possibly mean all the horrible things he says.” She gave as instances some of Trump’s most egregious remarks — calling women “pigs,” decrying a judge as unfair because of his Mexican ancestry and so on. At first, Clinton claimed, she couldn’t believe Trump meant these things either. “But here’s the sad truth,” she said. “There is no other Donald Trump. This is it.”

Certainly both these lines of attack are legitimate in their way. But the contention that Trump is a dishonest huckster, a fraud pretending to be something he isn’t, fits badly with the insistence that he’s brutally honest about his regressive opinions. You could certainly merge the two lines of attack into one – Trump is an authentic bigot who won’t keep his promises – but it doesn’t have much of a pop. Electoral politics isn’t and never has been the place for complexity and nuance.

You begin to suspect this to be yet another manifestation of Trump’s strange genius: embodying opposite forms of turpitude in such a way that accusing him of either doesn’t work. Like a composite artist listening to incompatible descriptions of the suspect and drawing a face that looks like nobody, Trump’s adversaries, if they’re not careful, may wind up sounding as opportunistic as the guy they mean to discredit.

Why, though, do Clinton and her allies and surrogates feel they need to say anything about Trump at all? Every campaign begins, disingenuously, by expressing the intention to stay “positive” and avoid “personal attacks,” and every campaign instantly and wisely reneges that pledge. But maybe this is the one instance in modern political history when keeping it would be an excellent idea. There is, after all, very little the Hillary for America campaign can tell the voting public about Trump that it doesn’t already know and have a semi-coherent opinion on.

For at least a year, Trump has dominated media coverage — dominated all forms of American political discourse, actually — by the simple expedient of being his outrageous self. Indeed, he has openly admitted that this is his aim, most famously in his 1987 book “Trump: The Art of the Deal.” “One thing I’ve learned about the press is they’re always hungry for a good story, and the more sensational, the better,” he writes. “It’s in the nature of the job, and I understand that. The point is that if you are a little different, or a little outrageous, or if you do things that are bold or controversial, the press is going to write about you. … I don’t mind controversy, and my deals tend to be somewhat ambitious. … The result is that the press has always wanted to write about me.”

Why assist Trump in his maniacal pursuit of ubiquity by calling attention to his outrageousness? Political campaigns’ criticisms of their antagonists inevitably sound hollow and disingenuous anyway, since they would benefit from those criticisms being taken seriously; so why not let others do the job? Of course, the Democratic Party is already heavily invested in the effort to ridicule and discredit Trump, so I have no hope of being heeded on this score. Prepare, then, to spend the next four months hearing that the Republican nominee is a forthright fraud. Or is it a duplicitous straight-shooter?