The one-page tax reform “plan” the administration released last month was mostly empty space. If you omit the hortatory language at the top and bottom of the page, it included exactly 107 substantive words about tax reform. (I counted!) Example: Under “Business Reform,” the administration says it will “eliminate tax breaks for special interests.” Oh? Which ones?

Experts cannot estimate the effects, such as how much tax revenue would fall, since the plan is mostly blank space. But heroic guesstimates based on Mr. Trump’s campaign proposals suggest tax revenue would fall by $5 trillion to $6 trillion over 10 years—and a lot more thereafter. Republicans will doubtless try to cover up this huge cost with trumped-up growth forecasts and legislative chicanery.

Then there’s the crowded congressional calendar again. Big tax proposals are hugely contentious and require enormous congressional time and energy. How, amid the Trumpian chaos, the health-care debate and more, will the House and especially the Senate find time to agree on a tax bill? A month ago, I was convinced Republicans would find a way to pass tax cuts, though not tax reform. Now, even that is in doubt.