You make a good point. But take an objective look at all the other responses on this page. How many of them contain the hidden assumption that Republican voters are stupid? I see a few. You might not be able to see it right away. You have to read them a certain way. Some have been downvoted and are light gray. But they are there.

And conversation here on HN is very restrained. When this news hits other social media, there will be more claims that Trump is stupid, Republicans are stupid, and any independent who is considering voting for a Republican is stupid.

So, yes, this article has unleashed a new wave of hatred in the world.

I have nothing against professional scientific writers writing a letter to the New York Times, or even writing an editorial there. In fact they should. I agree with you that it's good when they correct a specific claim with scientific evidence.

This is something else.

This is the whole Scientific American organization putting their stamp of approval on the idea that Republican voters are stupid.