Yingst: "And I have one quick follow-up, Sarah, on taxes. The President repeated this claim in the Oval Office today, saying we're the highest-taxed nation in the world. Why does the President keep saying this? It's not true, overall."

Sanders: "We are the highest-taxed -- corporate tax in the developed economy. That's a fact."

Yingst: "But that's not what the President said."

Sanders: "That's what he's talking about. We are the highest corporate-taxed country in the developed economies across the globe."

Yingst: "Sarah, so that's accurate, but the President keeps repeating this claim that we're the highest-taxed nation in the world."

Sanders: "We are the highest-taxed corporate nation."

Yingst: "But that's not what he said. He said we're the highest-taxed nation in the world."

Sanders: "The highest-taxed corporate nation. It seems pretty consistent to me. Sorry, we're just going to have to agree to disagree."

This. Is. Maddening.

Let's start with what Trump said -- and just keep saying -- about US taxes. It's pretty simple: "We're the highest taxed nation in the world."

So, on its face, the President is not telling the truth. And given that this claim has been fact-checked to death, there's no way he thinks he is telling the truth. But he just keeps saying it anyway.

Now to Sanders.

She, too, knows that Trump's oft-repeated claim that America is the highest (or "just about" the highest) taxed nation is totally wrong. But, when you work for this President, you can't say he was wrong about something -- unless you don't want to work for him much longer.

Sanders, caught between Trump's lie and the truth, tried to create a third way -- arguing that the US is the "highest-taxed -- corporate tax in the developed economy." (The US has the third highest corporate income tax rate in the world behind the UAE and Puerto Rico.)

As Yingst rightly notes, that's not even close to what Trump said. To which Sanders responds, "that's what he was talking about." Wait, what? The President's words matter. When he says the US is the most-taxed nation in the world, most people assume he means that the US is the most-taxed nation in the world. Not that the US has the "highest taxed corporate tax in the developed economies."

But it gets worse!

Yingst -- to his credit -- kept trying. He noted that what Trump has repeated time and time again is not at all what Sanders had just said.

"The President keeps repeating this claim that we're the highest-taxed nation in the world," he said.

"We are the highest-taxed corporate nation," she responded.

If you feel like you slipped down a wormhole into bizarro world, you're not alone. Down is up! Up is down! What Sanders is saying Trump said is exactly what Trump said!

The end of the back-and-forth is the worst part, however. As Yingst tried for a third time to make the point that what Sanders is saying and what Trump has said aren't the same thing, the press secretary cut him off.

"It seems pretty consistent to me," she said. "Sorry, we're just going to have to agree to disagree." (The next debate Sanders will have with reporters is what "San Diego" means .)

No! We aren't agreeing to disagree! We are agreeing that Sanders is wrong and Yingst is right!

This might seem like a minor point. It's not.

We know the President says things -- repeatedly -- that aren't true. But when the press secretary does it, too -- in the pursuit of some sort of positive (or accurate!) spin on an un-spinnable statement -- it suggests the problem of not telling the truth is epidemic in the White House.

Truth and facts are not negotiable. They can't be spun. They just are -- whether you choose to acknowledge them or not.