Hahahaha, good luck my friend! I think you're onto a seriously losing battle there. You should also maybe consider the battles you're fighting.

What happens if you convince this histrionic person of the error of their ways? Does anything change? Are you planning to do this with each of the histrionic people in the world? Or is this really about you getting to be right? (I only ask because I know this instinct very, very well in myself.)

If you want to change people's minds--and I think you're right to want to, I want to as well--simply being right isn't nearly enough. Statistics or a history lesson aren't going to change the mind of somebody who's emotional. You must have already discovered that numerous times.

I mentioned empathy in an earlier reply, and it's the piece that I think so many people on the rationalist side and on the histrionic side of these debates are missing. Very few of us truly "overcome our demons". Most of us just swap them for new ones which we decide are superior. And we prove they're superior by winning arguments with "the other side".

But if your goal is to have the other person go away with something to really think about, instead of a reason to write you off as an evil, unthinking, self-hating monster, you need to be able to demonstrate not only that you're right, but also that you understand where they're coming from. That's the sweet spot.