There’s a confusion at the heart of every presidential address to Congress. It’s supposed to be a grave occasion of solidarity around the principles of our shared republic, but it has the cheesy and disingenuous air of a campaign event. The address combines the solemnity of ceremony with mindless hyperpartisan hoopla — the shouting and booing, the symbolic gimmickry and, above all, the absurd tradition of signifying one’s agreement or displeasure by either standing to applaud or remaining seated after every phrase of the speech.

The address is designed for a traditional Democratic or Republican president. He’s meant to embolden his party and browbeat the opposition, with a few light gestures at unity and consensus. His allies are supposed to look gleeful and applaud his every gesture; his opponents are supposed to sit glumly on their hands and show the nation that they, at least, aren’t engaging in this misguided hysteria.

The address is designed, in other words, for a more or less ideologically coherent speech. But Donald Trump, as everybody knows, doesn’t care about ideological coherence. His ideas don’t fall along recognizable philosophical lines, with the result that his audience of lawmakers, ready to boo or cheer in the usual ways, often seemed unsure how to respond.

Once again, then, Trump succeeded in a setting where nearly everybody — including me — thought he would fail.

The Democrats looked especially awkward. So much of their detestation of Trump arises not from policy differences but from horror at his gaucherie and bizarre rhetorical excesses. But none of that is relevant in a State of the Union-style address. Subtract the issues of Obamacare repeal, immigration and the president’s hard-line policies on domestic security — the latter two of which don’t lend themselves to clear ideological allegiances — and much of what Trump had to say could have been said by any Democratic president. Even on the topic of health care, Trump offered several proposals that, taken on their own, most Democrats probably wouldn’t object to, hence making it rather difficult for them to do what they would have preferred to do, namely glower at the president’s let-them-eat-cake obstructionism.

What were Democrats supposed to do when, for instance, Trump vowed “to make child care accessible and affordable, to help ensure new parents have paid family leave, to invest in women’s health, and to promote clean air and clear water, and to rebuild our military and our infrastructure”?

I guess … we’ll applaud? Clap, clap?

Republicans, meanwhile, found themselves applauding for something not very unlike President Obama’s stimulus plan of 2009. “To launch our national rebuilding,” Trump said, “I will be asking the Congress to approve legislation that produces a $1 trillion investment in the infrastructure of the United States — financed through both public and private capital — creating millions of new jobs.”

I’m not sure what “financed through both public and private capital” means, but Trump’s jobs plan sounded to my ear like some socialist Five-Year Plan from the 1970s — making it all the more entertaining to watch congressional Republicans cheering like football fans who misheard the penalty call.

I wonder if Tuesday night’s address was a kind of adumbration of Trump’s presidency — his adversaries deprived of half their reasons for hating him, his allies stupidly wondering what happened to their principles, the nation’s commentators once again explaining why the president succeeded when he was supposed to fail, and voters reluctantly appreciating this hyperactive agitator who — for all his problems — at least keeps things interesting.