I don’t see what this sort of blatant denialism is supposed to accomplish other than demonstrating in-group loyalty.

That loyalty is a goal in itself for people not knowing any better.

For others it's a way to make Trump win.

What I don't get is how RFK Jr is still seen as something worse than a senile man and a man with terminal stages of neurosyphilis. He just has brain damage and some overvalued ideas, very well known and clear. While these two are simply not functional.

But then maybe it's good I live in another part of the world.