Just curious, if the MAGA base hasn’t been upset by being lied to thousands of times or by “big” reveals like the Access Hollywood tape or the Birthday Note, what makes you think anything, hypothetically even including a video of him raping an underage girl, would make them change their position?

Because this is something they really care about, it won't be coming from their (or Trump's) opponents, and there isn't a lie about it that Trump can tell they'll believe.

We're talking about the part of Trump's base that trusts Trump more than the Washington Post (for example). So it doesn't matter whether WaPo says that something's a lie. They don't trust WaPo, so the fact that they identify something as a lie doesn't affect their view of him. They don't believe the Access Hollywood tape reflects anything that Trump actually did (he was just making stuff up for Billy), nor do they believe the Birthday Note is real. It's just Trump's enemies out to get him.

But there's no "disbelief" that can come to Trump's rescue this time. This part of the base genuinely believes that there's tons of evidence of criminal abuse of children that the government has in its possession. That the government was sitting on that evidence because it wanted to protect the Corrupt Elite. That one reason that Trump was necessary - that the main reason that Trump was necessary - was that only someone outside of The Powers That Be would be willing to expose the evidence.

There's no dance around it. Trump can't say, "that's a lie," because it's not an idea that's coming from outside his base. It's coming from inside MAGA. It's the first time that he's going to have to tell MAGA that they're wrong about a MAGA truth, something that MAGA believed was true from the start.

That's really dangerous for him.