Whether they were triumphs or gaffes, defining debate optics have often characterized a candidate, and even a campaign. Examples abound: A pale, perspiring Richard Nixon next to a calm, cool JFK; Ronald Reagan's "I am paying for this microphone!" moment; George H.W. Bush looking at his watch as if he had another appointment; Al Gore's sighs and eye rolls; Rick Perry's "Oops," which derailed his 2012 and 2016 aspirations.

Most such signature scenes have taken place on the debate stage. Donald Trump's may have unfolded in absentia, as he held his own raucous rally to raise money for veterans while his Republican rivals debated.

So Trump became the story — again — and not just on Thursday, when his long-simmering Fox feud and subsequent debate no-show dominated headlines days before the Iowa caucuses.

Pundits pounced — some on Trump, but others on Fox for becoming the news itself. Iowa voters will have their say on Monday. What was undeniable, however, is that the theatrics typified a race that has upended assumptions in unprecedented ways; so applying campaign conventions to Trump's gamble might misinterpret developments in what is increasingly a fundamentally different political era.

"If we were talking about absolutely anybody else, this would be tantamount to suicide; people expect their candidates to debate," said Prof. David Birdsell, dean of the Baruch College School of Public Affairs at City University of New York. "This is seen not only as a test of mettle against competitors but as a way to connect with voters."

Birdsell, a nationally noted expert on the impact of political debates, spoke before Thursday night's events. "This is a guy who has been extraordinarily successful in blowing up every campaign maxim that we have committed to memory and believe to be inviolate," he added. "And they clearly are not inviolate if your name is Donald Trump. Does this hurt him? The answer will depend on who ultimately wins the frame."

In fact, the argument over the debate is only the race's latest malleable narrative. Some voters may sense Trump ducked debate scrutiny for an event he invented. Others may see a consistent candidate refusing to kowtow to "the establishment,"— even Fox News, which itself was a response to "the mainstream media."

"Those folks may well be able to walk away from Fox, and poke a thumb in the eye of Roger Ailes and a network that sometimes actually makes gestures to try to justify the 'fair and balanced' tagline," Birdsell said.

Usually it's Ailes himself poking a thumb. But the Fox News chief may have given Trump an easier out when the network issued a snarky news release mocking Trump's pre-debate protestations against moderator Megyn Kelly. Had Ailes just stuck by Kelly, the framing might have been that Trump was reluctant to answer tough questions. Instead, the GOP front-runner inverted it into a response to the network's disrespect.

So the well-replayed cuts from a long night of politics included split-screen images of the Trump jet juxtaposed against lower-polling candidates still reacting to the absent front-runner. Even Kelly couldn't resist. She began the debate with: "Let's address the elephant not in the room tonight."

It was a quick question that resulted in ready-made sound bites that may sate newer news appetites, but don't provide what's really needed: eat-your-spinach policy prescriptions. Sure, there were wonky moments during the debate. But don't look for them to rise above candidate quips and criticisms packaged as debate "highlights."

Birdsell said society (especially young people) has passed a tipping point in information gathering, so that recirculating two-minute reels suffices for two-hour debates. "So in some respect those (sound bite) moments become more important, because that's the only thing that people are going to see. But it becomes less important on the balance of performance — the sort of drab, mundane establishment of bona fides and qualities we typically assess (for) a sound case for leadership, because these never make the reels."

And, he added, these "drab assertions of confidence are more consistent with the habits of mind ... and the experience of leadership that might be pretty good indications if somebody would be an effective president."

Indeed, the other, more meaningful elephant in the room is that the campaign, as compelling as it's been, has mostly focused on politics, not governing. And governing will be needed — because beyond Thursday's split screen, a network of interconnected, international challenges from an increasingly complex, chaotic world awaits the next president.

John Rash is a Star Tribune editorial writer and columnist. The Rash Report can be heard at 8:20 a.m. Fridays on WCCO Radio, 830-AM. On Twitter: @rashreport.