What did Donald Trump do today?

He said that the United States does "very little business" with its largest trading partner.

In an interview with NBC News released today, Trump said this: 

Mr. Trudeau, who I call Governor Trudeau, you know, I said not Prime Minister, Governor—I said, "Governor Trudeau, could I ask you one question, why are we giving you $200 billion, why are we subsidizing Canada, if Canada was a state, it wouldn't cost us—it would be great—it would be such a great—we—it would be a cherished state, and if you look at our map, if you look at the [slurred speech]. When I look down at that, without that artificial line that was drawn with a ruler, many years ago, it was just a artificial line, goes straight across, you don't even [slurred] — what a beautiful country it would be, it would be great, but—I—I don't think the American public wants me to pay $200 billion a year to subsidize Canada. Again, remember this—we don't need their cars, we don't need their lumber, we don't need their energy, anything. We do very little business with Canada.

No country on earth does more business with the United States than Canada. It is the single largest consumer of American exported goods. In total trade, it is second only to Mexico.

Trump was occasionally slurring words, making it difficult to know exactly what he was saying, and much of what he could get out was nonsense. For example, the United States is heavily reliant on Canadian energy, so much so that Trump backed down immediately from some of his tariff threats in March when a single province, Ontario, began charging American utilities a 25% surcharge on exported electricity. 

Trump has repeatedly insisted that he believes that the "deficit" created by buying something is a bad thing for nations—as he does here. In reality, this is no worse than the "trade deficit" any given American household has with their local supermarket: buying things that are for sale usually benefits both sides. Waiting to buy food until a store needed precisely the goods or services you could supply in direct trade with them would probably end badly for both you and the store.

In any event, the "$200 billion" figure is more like $63 billion where Canada is concerned. That's roughly the size of the American trade surplus with the Netherlands, which by Trump's logic should try to annex the United States as its "thirteenth province."

Later on Sunday, Trump said he would put tariffs on movies (somehow) and insisted, all evidence to the contrary, that the only prices that are higher are "the, uh, the things you carry the babies around in." He apparently meant strollers.

Why does this matter?

• Past a certain point, a person's inability to grasp very simple concepts becomes disqualifying even if it's not a medical issue.