No, I am not saying this is a fact-free zone. What I am saying is that it is a zone for opinions, which may or may not be true (counterfactual may not be
the best word choice here, but it is close enough), and is not to be held to the same standard as wikipedia, whose copy you are using in what I read as a flippant remark.
I don't have data for you, just my perceptions and opinions. There are too many structural problems with the way political data is collected in this country (starting with the wording on questions in political surveys, and ending far beyond redistricting shenanigans). Given how deceptive and manipulative most election campaigns are, and how third parties are disproportionately disadvantaged financially, I don't think that looking at the proportion of left/right seats in congress is a good proxy for political polarization.
What I do see as a proxy is the behavior of those around me, and then trying to extrapolate that to reflect a larger population. I live in one of many pockets of conservativism in a very liberal state, and I am judging on the tone and tenor of political conversations and how freely friendly, amicable political debate flows among social groups in a fairly politically diverse area. Again, this is highly subjective for many different reasons, and I can say that I used to travel around a lot and have rubbed shoulders with many different social groups and castes in this society, and so I feel that I am at least somewhat qualified to extrapolate here.
And that observation is that political discussion is getting narrower, more pointed, and more focused on nationally-popular memes/issues. 12 years ago I sat in a meeting of one of the local tea-party chapters, and it was mostly older folks rabblerousing over local stuff. There wasn't much in the way of conspiracy theories, there wasn't a whole bunch of liberal shit-talking, just a bunch of people bitching about this-or-that with the local schooldistrict. When they happened to pick on my own high school, I knew that much of what they were saying was factually false, and I was able to state to the crowd why, and that was that. (There was some grumbling but the conversation turned elsewhere.) There were both left- and right-leaning folks in my friend group, and there was a quiet understanding to not get into political debates, and people weren't on-edge about it so if something was said, it didn't blow up.
We didn't have too many local crazies flying massive American flags on their trucks, with their cheap shots at trolling regular folks -- but now we do; there are places I can go where I can see them on a regular and predictable basis.
Nowadays I stay out of political shit, people are way too toxic, obsessive, and focusing on the same dozen or so things that everyone else is talking about. What would this tea party meeting have looked like today?
I have a different social group now; one that I like far more but we are very left-leaning, and increasingly (and troublingly) so. There is a much higher proportion of "polsplaining" (like mansplaining, but politicos talking down to people that offend them), many more suggestions that people self-evaluate (and insinuations that they are bad for towing a particular line), and hot political buzzwords are on people's tongues (and used as scapegoats) far more often than I can recall. I find myself hesitating to argue some points as I don't really want to die on any of these hills.
When the Roe v Wade decision dropped I broke my rule and attended a local rally, as I was pissed (much like everyone else). But at that rally someone got up on the podium and actively denounced people that not only just opposed abortion or womens health issues, but also anyone that opposed Black Lives Matter, anyone that opposed reparations, anyone that opposed ACAB; they kept calling for a unified front to address all of these issues as one.
I don't recall overhearing anyone complaining about feeling unable to speak up, but in the last year or two it has occurred multiple times at my usual haunts.
But once again this is all subjective experience of one person, albeit someone who tries to be at least somewhat perceptive and thoughtful about it. I have an axe to grind, so I am very quick to denounce certain cohorts -- hence my original comment here -- but again this is all subjective and nowhere have I explicitly asserted anything as fact. If you take the omission of certain wording as an attempt at factuality, you should consider that certain kinds of language training encourage writing in a way that minimizes some phrasing as a matter of style, and that it is very common in many places where people write professionally.