And so we are finally here, and not a moment too soon. Every insult has been hurled, every fact misrepresented; positions have been shifted and ventilated and dissected and caricatured.

We know, more or less (less, in the case of one candidate) where the next president will come down on critical issues such as health care, taxation, deficit spending and Iran.

But there is one question — a question of surpassing, even existential importance — that was the subject of not a single debate question or policy paper: Which candidate, Mitt Romney or President Barack Obama, would be better equipped to save civilization in the face of a global zombie uprising?

The mother of all 3 a.m. phone calls would begin like this: "Mr. President, very sorry to wake you, but it seems that a devastating pathogen has reanimated the dead and turned them into cannibals, and now they're feasting on the living, especially in the swing states of Ohio and Virginia. Would you like me to assemble those members of the Cabinet who aren't eating their deputies?"

A zombie invasion, although a low-probability event (only for the technical reason that zombies don't exist) represents, in the words of Daniel W. Drezner, the author of "Theories of International Politics and Zombies" and a Tufts University professor, "the perfect, protean 21st century threat — it's terrorism and biowarfare and pandemic rolled into one."

Drezner argues that zombies are a prism through which we can understand how governments react to supreme emergencies — of obvious relevance in an era when disaster seems to be visiting us with great frequency.

Zombies never seem to exhaust themselves as a subject of horror movies and fright literature. From time to time, popular interest wanes, but then along comes an attack like that of Sept. 11, or a dire recession, or a Hurricane Sandy, and people begin to contemplate the fragility of civilization and the limitations of government — just ask the people of Long Island and the Jersey Shore. As Drezner says, zombie movies and comics and television shows aren't actually about zombies: "What they're about is how humans react to the threat of zombies."

One problem a president would face, Drezner says, is that the zombie crisis, like so many today, might begin ambiguously: "When it emerges, it will be very, very hard to define exactly what the threat is."

Presumably, it would begin with some sort of terrible pathogen (the sort that has turned most of humanity into zombies on one of cable television's most popular shows, "The Walking Dead"), but the devastation wouldn't be immediate. The 3 a.m. phone call might begin more like this: "Something bad is happening, Mr. President, but we're not sure what."

Within days, though, it would become clear that in order to save what remains of humanity, a president would have to take the most dire and seemingly cruel steps imaginable, working in an atmosphere of paranoia and pervasive death and bureaucratic miscommunication.

"The problem with the undead is that they pose a nightmare for interagency policy coordination," Drezner says, noting the large number of federal organizations that would be required to fight the zombies.

So which candidate would be better equipped to make the decisions necessary to thwart this threat? To answer that question, we have to understand each man's vision of the role of the federal government.

Romney, we already know, isn't exactly enamored of the Federal Emergency Management Agency; we can assume he won't be doubling the budgets of the Centers for Disease Control and Prevention or the National Institutes of Health, the organizations that, with any luck, would find an antidote to zombification.

Obama, on the other hand, thinks the federal government should play a primary role in disaster management, and that government is generally a force for good. But there is a downside to overly generous federal spending: Drezner argues that the chance that a zombie pathogen could escape from a government laboratory grows as federal spending increases.

"The more biocontainment facilities built by the NIH and the CDC," he says, "and the more experiments and studies done on dangerous pathogens, the more likely it is that you could have a pathogen leak."

Something else works in Romney's favor: a commitment to a larger military. If martial law is declared — if whole cities need to be sealed off — the president is going to need high troop levels (although Drezner notes that a bigger Navy, such as the one Romney wants, would be of limited utility against land- based zombies).

Ultimately, this crisis would demand the sort of decisiveness few leaders possess. Romney might extend his theory of international relations to zombies, Drezner says, and simply argue that "the best way to defeat the zombies is to project strength and resolve." This would not, of course, be helpful against an enemy that possesses no higher brain function.

Obama's reaction, Drezner says, might not be calibrated for maximum effectiveness either: "He would initially try to project a large degree of calm, but unfortunately that could play out like Benghazi, and people would start asking, 'Why didn't they figure out what was happening?'" before announcing that the situation was under control.

I tend to think that during a global zombie uprising, citizens would grow mistrustful very quickly if they thought they were being told lies. Drezner thinks the same thing, and we both arrived at the name of a leader who might have the wherewithal to neutralize the zombie threat: New Jersey Gov. Chris Christie.

"He would get out there and say, 'Don't be a moron, these are zombies — if they bite you, you're gonna die,'" Drezner says. "What you need is someone willing to talk straight, someone with steady nerves."

Romney and Obama each have certain useful characteristics, of course: Romney proved himself to be a master of bureaucracy at the Salt Lake City Olympics; Obama has shown, with the assassination of Osama bin Laden, that he is ready to take lethal action even in the absence of definitive information. Both men, I think it's fair to say, would bring something to the zombie fight.

On the other hand, they might not be able to overcome the highly politicized recriminations that would begin at the outset of a zombie crisis and only intensify as the situation deteriorated. It is safe to assume that, if a Republican were president during a zombie invasion, liberals would blame the crisis on Halliburton and George W. Bush. If a Democrat were in charge, conservatives would blame Obamacare.

We are living in an age in which the velocity of cataclysm seems to be accelerating. Combine that with political dysfunction and widespread cynicism, and you have a formula for eventual disaster, with or without zombies.

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Jeffrey Goldberg is a Bloomberg View columnist and a national correspondent for the Atlantic.