An old political science professor of mine used to joke that the very term "political science" was an exercise in self-importance. It's not really a "science," even if professionals in the field secretly wish they could wear white laboratory coats and perform proper research in a controlled environment. The problem is, no political scientist gets to, say, become a dictator of a country and deliberately starve its people to see if they take up arms against him. Or, to take another example, become president of the United States without having any idea what he's doing.

But now we have Donald Trump. This is the experiment political scientists have been waiting for. What would happen if America didn't have a competent president? We're finding out.

It's not quite right to compare President Trump to Tom Hanks' character in the classic comedy Big, as the 13-year-old-in-a-man's-body portrayed by Hanks ultimately succeeded in his corporate job precisely because of his innocence. Trump is blithely ignorant, but far from innocent. A more apt comparison may be the pickle Chevy Chase and Dan Ackroyd found themselves in when they posed as surgeons in Spies Like Us, or when Clint Eastwood's Dirty Harry pretended to be a pilot in Magnum Force ("Excuse me, captain, I know this may sound silly, but, can you fly?" "Nope. Never had a lesson.")

Trump has no idea how to run the federal government. This prospect is at once terrifying and comically absurd. It's also a profoundly intriguing, real-time poli-sci experiment: Can America — roughly speaking, the interlocking structures of its government, economy, and civil society — run without a president? Can America survive being "led" by a 70-year-old glorified scam-artist who's addicted to watching TV?

Speaking to Washington Post columnist Dana Milbank, national security expert Tom Ricks surmised that a competent national-security apparatus can cover for a multitude of ignorance: "We're now experiencing what a decapitation strike would be against the U.S. government … You can have nobody, effectively, at the White House and still run the country. It's a post-nuclear environment." The incident that provoked Ricks' quote, in this case, was Trump's laughable assertion that he had sent an "armada" as a we-mean-business message to the North Korean regime. Except that the "armada" in question was sailing in the opposite direction.

Evidence of Trump's lack of preparation for the job emerged just days into his pre-presidency when he learned that he would have to hire an all-new West Wing staff. New evidence rolls in on a weekly, sometimes daily, basis. (And, as you've no doubt heard, we're not even 100 days into this hot mess.) Trump has no idea, for instance, how the NATO alliance is financed and only recently reconciled himself to its continued existence. This, after repeatedly complaining of its obsolescence.

More, he has no idea how trade with countries in the Eurozone works. When German Chancellor Angela Merkel was in Washington last month, Trump had a difficult time understanding that the U.S. could not strike bilateral trade deals with Germany. "You can't do a trade deal with Germany, only the EU," he was told, according to a Times of London report. "On the 11th refusal, Trump finally got the message."

Then there was the bungled effort to repeal and replace ObamaCare — a direct consequence of Trump not understanding the legislative sequence that House Speaker Paul Ryan had talked him into, as well as Trump's invincible ignorance of and lack of interest in the details of health-care policy itself.

Additional tales of Trump's intellectual woes are too legion to fit this space.

Unlike the withering assessments of the president we hear from Trump-era comedians, elite journalists simply don't know how to handle the extent of Trump's lack of preparedness and knowledge. They are compelled by an unwritten professional code to speak of Trump in such measured tones as you find here, from The New York Times' Peter Baker:

For any new occupant of the White House, the early months are like a graduate seminar in policy crammed into every half-hour meeting. What made sense on the campaign trail may have little bearing on reality in the Oval Office, and the education of a president can be rocky even for former governors or senators. For Mr. Trump, the first president in American history never to have served in government or the military, the learning curve is especially steep. [The New York Times]

Let's just say that "especially steep" is a polite way of putting it.

The truth is, Trump does not have the intellectual bandwidth or the temperament to handle the presidency. This was obvious from the moment he began running for the job. Every day that doesn't result in catastrophe is a day to marvel at the chance we have to observe a superpower without a mentally proficient executive or a functionally competent staff.

For those not averting their eyes, be sure you're taking notes.