After the Dow Jones industrials plunged 832 points on Wednesday, Larry Kudlow, President Trump's chief economic adviser, walked up the White House driveway and proclaimed that there was no cause for concern. Not about the stock market, or turmoil in China's economy, or American casualties of Trump's trade fights, or the president's attempt to bully the Federal Reserve into an easy-money stance.

"Our economy and the people and the workers and entrepreneurs, they're killing it. We're the hottest in the world," Kudlow proclaimed in front of the CNBC camera. "We're crushing it right now, and I think that's going to continue regardless of China."

Kudlow, standing outside the West Wing, offered versions of this happy talk — “I don’t think this is anything resembling a sugar high ... America is on a tear” — to any other reporter who would listen.

But the Pollyanna performance didn't play well on Wall Street. The Dow lost another 546 points Thursday. The index had a partial recovery Friday but finished the week down 4.2 percent, the third straight weekly decline.

Maybe that's because investors had heard Kudlow say such words once before.

Ten months before the crash of 2008: "There's no recession coming."

Seven months before the crash: "The economy will be rebounding sometime this summer, if not sooner."

Six weeks before the crash: "An awful lot of very good new news."

Markets rise and markets fall, and this last week's volatility doesn't necessarily mean the economy will tank. But it does show the limits of Trump's hucksterism.

Though Trump called the stock market a “bubble” during the campaign, he has boasted scores of times about new records it has set during his presidency. On Saturday, he told a crowd: “Your 401(k)s, you all look like a bunch of geniuses — thank you, Donald, very much.” So far, that has worked, because economic growth has continued under Trump, and indeed accelerated after the massive stimulus of a tax cut and spending increase. Republicans would otherwise be facing bigger losses in next month’s midterms.

But now come scattered signs of trouble. The Fed has been raising interest rates — in part because Trump’s massive stimulus during an expansion threatens to set off inflation. China’s economy has been unstable, in part because of Trump’s trade dispute.

And though the trade deficit with China hit a record in September, Trump's tariffs have hurt many U.S. producers; Ford, claiming the tariffs cost it $1 billion, is planning workforce cuts.

No amount of fact-checker Pinocchios will stop his followers from accepting Trump’s word that Robert S. Mueller III is on a witch hunt, global warming is a hoax, North Korea no longer is a nuclear threat and Democrats are a dangerous mob. But they can feel the economy personally. When the downturn comes, huge deficits, which Trump widened, will leave the federal government with little power to cushion the fall. If this happens on his watch, even Trump’s ardent supporters would see it’s not fake news — and that would be the end of him.

Trump needs reassurance — and Kudlow, the former TV business pundit, now plays the carnival barker’s carnival barker.

With cameras in the room for a prescription-drug bill signing Wednesday, Trump introduced "the great Larry Kudlow, whose voice is so beautiful. ... The economy, Larry, how is it doing?"

"Couldn't be better," replied Kudlow.

And Kudlow's message couldn't be otherwise:

Oct. 7: "Right now, the American economy is crushing it."

Sept. 28: "We're crushing it, we're absolutely crushing it."

Sept. 17: "We're crushing it."

Sept. 6: "We're crushing it."

Aug. 28: "America today is just crushing it everywhere."

Aug. 17: "We are crushing it. And people say this is not sustainable, it's a one-quarter blip? It's just nonsense."

In Thursday’s interview, Jim Cramer, Kudlow’s former partner on CNBC, tried to temper Kudlow’s mania. Cramer cautioned about a slowdown in business in key economic sectors, a peak in real estate, slower lending, declining demand for luxury goods — “a pastiche that I’m concerned about.”

Kudlow brushed off the worries. "I'm just saying there's so much good news out there that we shouldn't just try to find a couple of numbers that don't look great, okay?" he said. "This is a heck of a story. Let's embrace it."

Sound familiar? "The Bush boom is alive and well," Kudlow said before the 2008 crash, calling the soon-to-collapse economy "still the greatest story."

Until it wasn't.

Dana Milbank | The Washington Post

Follow Dana Milbank on Twitter, @Milbank.