In theory, the question should have been easy.

Debate moderator Linsey Davis on Tuesday night pointed out to former president Donald Trump that he had repeatedly promised during his first two presidential bids to present a new approach to health care. She pointed out, too, that he hadn’t delivered one.

“So tonight, nine years after you first started running,” Davis said, “do you have a plan, and can you tell us what it is?”

Trump treaded water for a bit, bashing the Affordable Care Act but also taking credit for “saving it.”

Davis was not hoodwinked. “So just a yes or no,” she followed up: “You still do not have a plan?”

“I have concepts of a plan,” Trump replied.

Don’t we all, Mr. Trump. Don’t we all.

This should theoretically have been an easy question because Trump should have assumed someone at some point would ask. Davis was responding specifically to Trump’s most recent promises to revamp access to and the cost of health care, but she was also responding to those literal nine years of similar promises. When Trump pledged a new health-care policy shortly before the 2020 election, I created this chart showing his past similar promises, none of which had been kept. (You will note that the line labeled “now” is not actually now.)

Over and over, promises of a new health-care plan. Over and over, no plan. Or even concepts of one.

Trump’s failures to deliver on his health-care policy promises in particular are punchlines in his political career, surpassed only by his efforts as president to launch “infrastructure week.” Remember that time Trump handed a journalist a giant binder of paper with his policy proposals, only to have her visibly flip through a few pages that were blank? That was his health-care plan! Or, it seems, some of the concepts.

So, again: Trump should have had an answer. Except that, as I wrote on Wednesday, he’s not used to having to answer difficult questions. He’s not used to being in a place where the interviewer isn’t sycophantic and he can’t simply walk away. Davis had a unique opportunity and earned a revealing response.

The damage done, though, wasn’t simply in the clumsy phrasing, one that will live alongside “alternative facts” in defining an aspect of Trumpism. Nor was it simply that it revealed the hollowness of all of those Trump promises on health care. It was also unusually problematic for Trump in this moment against this opponent.

Trump and his allies have spent the past few weeks pillorying Vice President Kamala Harris for having no delineated policy proposals. This is ironic in part because Trump in 2015 publicly rejected the idea that voters actually cared about such proposals (which is generally true). But, still: This was one central line of attack. On matters of policy, his team insisted, Trump would prevail over Harris easily, in part because she had nothing to offer.

What does Trump have to offer? Well, concepts of plans.

His supporters will counter that he does have policy proposals, ones articulated in what his team calls “Agenda 47.” It was presented largely through video snippets in which Trump talks generally about things he wants to do, most of them very familiar. This section of his website has been de-emphasized in favor of the “platform” Trump helped write for the Republican convention (which is somehow even vaguer). But when I looked at it in June, there was no specific proposal on health care — and very few mentions of it in general. (Search for yourself!)

This has made it much easier for Harris and her allies to suggest that the thick sheaf of proposals compiled by the Heritage Foundation — the infamous “Project 2025” — is what Trump actually plans to do if he is elected again. Trump correctly points out that the descriptor “Trump’s ‘Project 2025’” is misleading, since he didn’t write it. But his critics correctly point out that the authors of the document are largely people who worked for Trump when he was president and can be expected to return to the federal government if he wins. And, since Trump has no plans of his own, their plans would become his.

It is okay if Trump doesn’t have a detailed proposal for overhauling the health-care system. It is a system that is notoriously complicated and involves countless competing priorities. It is one in which expense is unevenly distributed, making it that much harder to figure out a fair way to cover the costs. The reason the Affordable Care Act was such a big deal in the first place (to paraphrase Joe Biden) was that it managed to address a significant chunk of the issue in one fell swoop (through a clunky and patchwork process).

But for that reason Trump should stop pretending he has a plan. It’s not that people thought he did, mind you. Even when he first started touting his imminent proposal, it was understood that he was blowing smoke. Donald Trump, the political neophyte who shrugs at policy details, was not going to be the person to slice this Gordian knot. But he keeps saying it because he says untrue things all the time, and his supporters grant him the benefit of the doubt.

Trump’s “concepts of a plan” comment, though, will make it that much harder for anyone else to grant him that benefit before Election Day.