For quite a while, on a nearly daily basis, Donald Trump claims that the United States is “the highest taxed nation in the world.” And every time he repeats the line, reality-based observers remind the president that he’s lying, which apparently has no effect on him, since he keeps saying it anyway.

This morning, reporter Mike Sacks asked Trump why he keeps publicly pushing a line he knows to be objectively false.

SACKS: With the credibility you need to pass tax reform, why do you– TRUMP: Some people say it differently, and they’ll say we’re the highest developed nation taxed in the world. SACKS: And why don’t you say it that way? TRUMP: Because a lot of people know exactly what I’m talking about it and in many cases, they think I’m right when I say the highest. As far as I’m concerned, I think we’re really essentially the highest, but if you’d like to add the “developed nation,” you can say that too. But a lot of people agree that the way I’m saying it is exactly correct.

What we’re left with is a situation in which the president has tried to clarify a lie by telling new lies, which is almost impressive in its own exasperating way.

First, Trump may like to believe that “a lot of people” say he’s telling the truth, but those people don’t appear to exist.

Second, even if his new claim is taken at face value – if we limit the scope to advanced, “developed” economies – Trump is still wrong. The United States isn’t close to being the highest taxed “developed” nation, either.

As for why, exactly, Trump continues to cling to this lie with such enthusiasm, he still seems to think it’s necessary – because the truth won’t get him what he wants.

If the president acknowledged that the United States is one of the lowest taxed nations in the developed world – in other words, if he noted the truth – he’d lose his principal talking point in support of the Republican Party’s tax plan. The lie serves as a foundation, and without it, the structure crumbles.

Alternatively, Trump could argue that the GOP’s tax plan is needed to help a struggling economy, but to date, the president has argued that the exact opposite is true: the economy, thanks to how awesome Trump’s awesomeness is, is doing great.

So why is it necessary to approve massive tax breaks to the wealthy and corporations? Because, facts be damned, the U.S. is “the highest taxed nation in the world” – a lie Trump apparently intends to keep telling.