You can see this collapse several ways. One is through surveys of business executives, who spent Trump’s first two years being very bullish, but have now become remarkably pessimistic.

You can also see it in the bond market, a much better indicator of economic expectations than the stock market. Long-term interest rates tend to be high when investors expect a booming economy, in which the Fed will tighten money to head off inflation; they tend to be low when investors expect protracted economic weakness and easy money as far as the eye can see.

And 10-year bond rates have plunged, from more than 3 percent last year to 1.75 percent as I write this. The last time we saw this kind of plunge was 2010-11, when investors finally realized that recovery from the Great Recession was going to be slow and painful, not a repeat of “morning in America.”

So what happened to the Trump boom? The collapse in confidence began late last year, when it became clear that Trump was serious about waging trade war on China; it continued as evidence accumulated that the 2017 tax cut was a big fizzle, doing basically nothing to boost business investment and providing at most a brief sugar high to overall growth.

But the truth is that even pessimists expected the tax cut to do more good, and the trade war less harm, than they did. Why have things turned out so poorly? One answer, to which I’ve subscribed, is that in addition to its direct impacts on U.S. exports and businesses that rely on Chinese suppliers, the trade war has created damaging uncertainty. Businesses that rely on global supply chains won’t invest for fear that the trade war will get even worse; but businesses that might move in to replace imports also won’t invest for fear that Trump will eventually back down.

I suspect, however, that there’s even more to the story. Business interests spent a long time in denial, but now even they are facing up to the reality that Trump and his team are very strange people who have no idea what they’re doing — and the uncertainty that reality implies.

I mean, considering that trade confrontation with China is the centerpiece of Trump’s economic policy, it’s not reassuring to learn that his trade war czar, Peter Navarro, has an imaginary friend — a source named “Ron Vara” whom he has repeatedly cited in his books, but who doesn’t exist, and whose name is in fact just an anagram of “Navarro.”

Next year’s election should be about Trump’s betrayal of his oath of office. Realistically, however, it also matters that the economy probably won’t be his friend.

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