Considering the standard of the rest of the thread as it is, I don't see how it could get much worse, but you're the boss.
It's not that the thread would get worse, it's that it would get lost in the shuffle.
I guess I can nutshell it as: I think your standard for which views are unconscionable (rather than just mistaken or bad) is awfully low, given that you apparently find so many people here to be totally irredeemable in a group that looks, to me, like a relatively normal cross-section.
In any case, I have wondered if this might genuinely be a factor that prompts users to give up on the place and result in the site starting to stagnate.
I hope you'll understand why I'm skeptical of a diagnosis that boils down to "not enough people here agree with me about politics."
But I think you're still in the right general area: I don't think people are willing or able to compartmentalize disagreements any more, and I don't think they have any sense of degree or perspective. I think, when I started this place, there were views someone liked, and views they disagreed with but kind of understood, and views they disliked but didn't despise...and now there's pretty much just "what I believe" and "ideas I despise." And if you despise someone, even for just one belief, it makes it unpleasant to interact with or around them at all.
The solution is simply having the empathy required to figure out how intelligent and well-meaning people might reasonably come to different conclusions.