Donald Trump is an effective salesman, but he’s a terrible propagandist. And when it comes to the big things he and the Republican Party want to accomplish while he’s president, the ones that require legislation, his inability to shape public opinion could be their undoing.

I’m going to lay out the multi-step process by which Trump undermines Republican efforts, but if you’re wondering how it is that Republicans can have total control of Washington yet seem unable to pass any legislation that accomplishes their key goals, the limit of Trump’s influence over public opinion is a big part of the answer.

Just look at the budget bill Congress passed yesterday to fund the government through September. It caved on one item after another that Trump had hoped to include, from the border wall to defunding Planned Parenthood to drastic cuts in the National Institutes of Health and the Environmental Protection Agency to cost-sharing subsidies under the Affordable Care Act.

That last item leads me to a perfect example of how Trump’s weaknesses and ignorance make effective propagandizing so hard for Republicans. Let’s look at a part of the interview he gave to “Face the Nation” yesterday, about the latest iteration of the GOP’s replacement for the ACA. The entire exchange is too long to reproduce, because it involves a lot of barely decipherable Trumpian word salad, but the key part starts with Trump insisting that the Republican bill guarantees coverage for those with preexisting conditions.

“Preexisting conditions are in the bill,” Trump says. “And I just watched another network than yours, and they were saying, ‘Preexisting is not covered.’ Preexisting conditions are in the bill. And I mandate it. I said, ‘Has to be.'” Host John Dickerson, knowing that this is completely false, goes back and forth with Trump, trying to clarify that he is actually saying what he appears to be saying, while Trump circles around the point and goes off on some tangents. Here’s how the sequence ends:

DICKERSON: So I’m not hearing you, Mr. President, say there’s a guarantee of preexisting conditions.
TRUMP: We actually have — we actually have a clause that guarantees.
DICKERSON: Okay, excellent. We got there.
TRUMP: We have a specific clause —
DICKERSON: Let me ask you —
TRUMP: — that guarantees.

Just to be clear, the most significant change in the latest Republican health-care bill is the way it screws over the tens of millions of Americans with preexisting conditions. As the price of winning the support of the ultra-right Freedom Caucus, Republicans included a provision allowing states to permit insurers to charge whatever they want to patients with preexisting conditions. States can waive “community rating,” the ACA’s mandate that insurers charge everyone the same rate (depending on their age) regardless of their medical history.

This effectively destroys the ACA’s guarantee that those people can get coverage, because if an insurer can say to you, “Hmm, well since you have diabetes, we’ll offer you a plan, but your premium will be $100,000 a month,” then it’s the same as them being able to deny you coverage.

The result of this interview is that now, Trump has gone on record in a very public way promising that the Republican plan guarantees coverage for those with preexisting conditions, full stop, which is the opposite of the truth. He thus initiates a series of reactions and counter-reactions that is extraordinarily problematic for Republican hopes of passing the bill. Here’s how the whole thing plays out:

  1. Republicans propose legislation with incredibly unpopular provisions.
  2. Trump, wanting to claim to be on the side of what’s popular, lies about what the legislation does.
  3. Journalists, who by now are on guard for his lies, call him out on them.
  4. Other Republicans are asked to defend his lies about the legislation, which they find very difficult to do.
  5. The ensuing attention to the very unpopular provision of the Republican legislation increases resistance to it.
  6. Realizing they’re losing the debate, enough Republicans bail on the legislation to doom it.

For a propaganda campaign based on false premises to be successful, you need (among other things) for your entire side to be unified in how it makes its case. That will encourage the press to fall back on its habitual “He said/she said” style of reporting, which will enable your deception to pass to the public without too much resistance. But Trump makes both of those things impossible. Republicans such House Speaker Paul D. Ryan may try to glide over potential public opposition with clever rhetorical formulations, like saying that they support “universal access” to coverage, which they hope people will hear as akin to “universal coverage.” That only works if everyone on their side says it over and over again, but the person on their side with the biggest megaphone of all can’t be trusted to toe the rhetorical line. Instead, he just reaches for whatever sounds the most popular, saying things like “We’re going to have insurance for everybody.”

Because those assertions are so blatantly false, and because Trump has lied so often in the past, journalists quite reasonably approach any Trump statement assuming that he’ll probably say untrue things, and that when he does they have an obligation to point them out. The whole discussion ends up being framed around the question of this unpopular move Republicans are trying to make, and how they’re trying to deceive people about it. And that’s where the propaganda effort falls apart.

If Trump and the Republicans were trying to do something popular — say, increase the minimum wage — they wouldn’t have to be sneaky about it, and Trump’s impulse to say whatever he thinks people want to hear wouldn’t be so much of a problem. And if they had a different president, they could mount a more effective propaganda effort and perhaps pass unpopular bills.

Consider their top three legislative priorities at the moment: a bill that would throw tens of millions of Americans off their health insurance, a massive tax cut for the wealthy and a financial deregulation bill so generous to Wall Street that it practically requires every American family to send their first-born child to the Hamptons to wash a Goldman Sachs partner’s car for him. All these bills are complex and politically perilous, so if you want to pass them, you have to carefully manage public debate, which Republicans can’t do as long as Donald Trump is the leader of their party.

That doesn’t mean that all those efforts are guaranteed to fail completely. On tax cuts in particular, Republicans want them so desperately that chances are they’ll pass something even if it’s unpopular. But it’s ironic that the guy who made a career out of managing his media image and convincing people to buy his crappy products and services turns out to be the biggest hindrance Republicans have in selling their agenda to the public.