Donald Trump speaks at a campaign stop in Lowell, Mass., on Monday. (Charles Krupa/Associated Press)

The emperor has no clothes. The Donald has no policy.

This is not exactly news, but it is too often forgotten in the substance-free carnival that is the 2016 presidential race. Donald Trump’s bright-shiny-object campaign style serves to obscure the substance void, leaving reporters endlessly chasing after his latest rhetorical bomb rather than pressing him on policy.

Not, of course, that such questioning produces answers. Trump evades questions about how he would approach a particular problem with airy assurances about management and dealmaking. There’s only so much follow-up that can be done in the face of this bombast.

Join me on a trip through a typical Trump stump speech, this one an hour-long stream-of-consciousness ramble just before the new year in South Carolina:

The crowd size. His poll numbers. Why he must attack Hillary Clinton. The media is the worst. The trade deficit with China. How much money Jeb Bush has wasted. Has he mentioned the polls? Matt Drudge, great guy. How bad a job Clinton did at State. How nice of Vladimir Putin to praise him. (No sarcasm intended.) His Ivy League pedigree and big vocabulary. Back to Clinton: “She just gives me a headache.”

At a campaign event in Hilton Head, S.C., Republican front-runner Donald Trump criticized Jeb Bush for overspending on political advertisements and low poll numbers. (Reuters)

He’s going to build the strongest military ever. Obamacare is a disaster. Common Core’s dead. Trump’s spent no money on his campaign and he’s No. 1. Marco Rubio, nice guy but what about those somber ads with a black background? What great ratings those debates got.

Not smart to answer questions about the Islamic State — he wants to be unpredictable. How bad the Iran nuclear deal is. The Iraq War, huge mistake. The environmentalists’ attack on Trump’s hair spray and how the spray is much better than the pump, with those blobs that get stuck and he needs to take a shower. By the way, he lives in a very nice apartment, and “I don’t think anything gets out” into the atmosphere.

The hoax of global warming and the threat to the universe. Speaking of the universe, Miss Universe, and “oh, did I get rich” off the pageant.

How many televisions he orders a year from South Korea and how we are using our military to support countries such as South Korea that don’t need our help. His wall versus the Great Wall of China. Even his hats are made in America, and you can buy other things on his website, too.

Carly Fiorina’s a nice woman.

China’s building military fortresses in the South China Sea and we’re worrying about the environmental impact of a border wall with Mexico on toads and turtles? Wait until China has to deal with Carl Icahn.

Don’t worry about the cost of a wall. The Old Post Office building is coming in under budget. As is his campaign.

By the way, Clinton has lower energy than Bush. Trump’s a nice person. He actually wants to help Syrian refugees, with a massive safe zone. Can you believe Angela Merkel was the person of the year and he wasn’t? The wall — Mexico’s going to pay.

Ted Cruz, he’s a good guy.

Remember the escalator in Trump Tower? The press that day looked like the Academy Awards. No one would be talking about illegal immigration if it weren’t for Trump. More polls.

Bernie Sanders, a total disaster who wants to raise your taxes to 90 percent.

Back to Clinton: He’s the last person she wants to run against.

Trump will save the Second Amendment. If only Parisians had guns. It wasn’t politically correct for neighbors to report Islamic State sympathizers in San Bernardino, Calif. Trump’s poll numbers went up after the attacks.

The trade stuff is easy. How we messed up Iraq. We’re going to be rich, safe, strong again.

Readers, this is no caricature — it’s Trump unfiltered, alighting briefly on a topic, complicated or trivial, before flitting to the next. And it’s not as if Trump bolsters his stump speech with policy depth in proposals or interviews. If Obamacare is a disaster, what’s Trump’s replacement? If Common Core is dead, what’s his alternative?

The nonpartisan Tax Policy Center has estimated that Trump’s tax plan — one subject he barely mentions — would cost $9.5 trillion over the first decade, not including added interest. In 2000, when a surplus was forecast, George W. Bush proposed cuts costing $1.3 trillion. They were extensively debated — in the campaign.

Trump relies on his ability to dominate the news with provocative distractions, to repel serious questions until interviewers’ time runs out. We in the media must find a way, if not to pierce the bluster, at least to expose it.

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