Shane Goldmacher has an eye-opening report in Politico headlined “Where Trump Gets His Fake News” that primarily focuses on White House aides’ ability to influence the course of events by showing Trump news stories that aren’t necessarily true. Deputy National Security Adviser K.T. McFarland, for example, shared with him an internet hoax about a fake Time magazine cover story from the 1970s, and former Deputy White House Chief of Staff Katie Walsh’s standing was fatally wounded by an unsourced story on GotNews.

But Goldmacher also offers an explanation for the somewhat mysterious timing and content of Trump’s late-April tax reform rollout, which lacked any kind of real detail or forward progress relative to a hazy blueprint he released during the campaign.

And now we know the reason is that Trump hastily cut off the policy development process in response to an op-ed:

More recently, when four economists who advised Trump during the campaign — Steve Forbes, Larry Kudlow, Arthur Laffer and Stephen Moore — wrote in a New York Times op-ed that “now is the time to move it forward with urgency,” someone in the White House flagged the piece for the president. Trump summoned staff to talk about it. His message: Make this the tax plan, according to one White House official present. The op-ed came out on a Wednesday. By Friday, Trump was telling the Associated Press, “I shouldn’t tell you this, but we’re going to be announcing, probably on Wednesday, tax reform,” startling his own aides who had not yet prepared such a plan. Sure enough, the next Wednesday Trump’s economic team was rolling out a tax plan that echoed the op-ed.

To be clear, of the four op-ed authors only Laffer is an actual economist with a PhD. And the plan the White House ended up putting out doesn’t exactly follow the blueprint laid out in the op-ed in all its details.

But it absolutely does reflect two core ideas from the op-ed that constituted a reversal from the previous trajectory. They called on the administration to release a tax plan fast and they called on the administration to keep it simple with aggressive rate cutting and not too much worry about pay-fors.

That was a sharp contrast from the framework that House Speaker Paul Ryan and Ways and Means Committee Chair Kevin Brady had spent months working on. As Brady explained to Vox in March, he worried that “if we just do rates, lower rates, and don’t redesign our code to be competitive with the world, it will be as if we got supercharged new fuel for our car but it’s an old clunker that can’t compete with the modern version on the road today from China, and Europe, and Canada, and Mexico.” And that meant aiming for a deficit-neutral tax reform concept.

That, in turn, is how House Republicans ended up settling on the idea of a destination-based cash flow tax, and then how National Economic Council Chair Gary Cohn spent months kicking around ideas like a value-added tax or a carbon tax as ways to pay for big supply-side tax cuts. The Forbes/Kudlow/Laffer/Moore op-ed urged Trump to ditch all that and just focus on big deficit-boosting tax cuts. And so Trump threw all that work overboard on impulse and had his team rush out a half-baked tax plan in a week.

It’s a hell of a way to run a railroad.