Please don't. We definitely need to be mending the gap.
I'm reviewing and revising my last comment here; I wrote it shortly after waking, yesterday, and your comment makes me concerned that I came across as one of the people saying "yes but the other side is evil!!!" when that's not what I wanted to say at all.
I'll be editing the last comment to make it more clear but in the meantime is like to clarify here, too: this affective polarization that the OP discusses is definitely happening. But you can say it directly and there will still be people who respond with "Yes, but..."
Yes, but the other side is really actually evil.
Yes, but this decade is different.
Yes, but they hated us first.
People caught up in this rage based polarization aren't simply polarizing because of their affect (i.e. feelings). Those feelings are part of a massive complex of beliefs and behaviors that all support the polarization.
So if a well meaning academic wades into the fray screaming about feeling, alone, causing polarization, they'll be greeted with a chorus of "Yes, but" as people acknowledge that the academic has a point but insist that this time is different.
It's on the academic to explain how this time is NOT different. Because that's what a good academic does; they take on the burden of explaining clearly and fully, in a world where most others do not.
In this case, explaining clearly and fully means that the OP has to go way beyond talking about affect and emotion. They have to talk about how those things warp thought.
Both sides of the political spectrum do things that are antagonistic to the other. However, there seems to be a societal process involved in politics (much of which involves the news, and the choices of party leadership) where the actions of political opponents are taken and inflated into a "mythos" about a massive, monolithic, evil group on the other side who is hostile to our values and out to get us.
Gingrich is a good example because if you review his leadership you can see as he trained the Republican party to fight dirty; he deliberately shifted the rhetoric of the right wing to stoke rage in the Republican base. You can watch as the Republican master narrative was constructed over the course of several decades. It was a deliberate form of political engineering, meant to increase affective polarization.
The biggest change I have seen in the last decade and a half is that the Democrats are now doing the same. I don't know if it is a natural reaction to what the Republican party has done for years, or if it is more political engineering started by left wing leadership. Knowing politics I would be unsurprised if it is both.
The point is, OP has a lot of ground that he needs to cover of he wants to talk about affective polarization. I'm pretty convinced that it explains what's happening, but if the author wants to be effective and not dismissed, he has to do a lot of explaining to make sure people understand that it's not just a simple story of people getting angry and polarizing. It's a complex story where parties stoke rage aa political tool, and that rage warps the way we select and filter information when building our understanding of who the other side is, and how they behave, and what their motivations are.
Simple talk about emotions won't do. Until people can see the full picture and understand that a lot of their "yes, but..." arguments are the product of rage engineering by people who benefit from keeping them angry, we won't see a change in this polarization.
