Sorry, but in what possible sense is 'white people discussing their superiority to non-whites' part of the overton window, especially in a way that it wasn't before 2016? In what sphere is is remotely acceptable now where it wasn't before? 

https://www.lesswrong.com/posts/KpMNqA5BiCRozCwM3/social-dark-matter#IV__Interlude_i__Nazis
 

Literally the exact opposite is true. Intelligence researchers who research and report on the fact that black Americans have lower average IQ than white Americans and who do not dogmatically assume that it results from non-genetic factors are having a much harder time now than ten years ago. Many have been hounded out of their universities by "anti-racist" activists, others have found themselves fired on the basis of extremely weak 'conduct breaches' or been cut off from crucial databases and funding etc. And in any case, these people's continued careers largely depend on most people not knowing this is what they research - not that any of this has any kind of mainstream political acceptability.  

Even on social media, I've been banned for literally just stating the fact that blacks average around one SD less of IQ than whites, with no indiciation of the cause or political implications of this difference - before 2016 I could debate people in a much more open manner and not get banned. 

Look at Nick Bostrom - he was once comfortable expressing his belief that heritable differences between human populations included intelligence, but in this post-2016 world he's been forced to recant that heresy. 

Think of any major institution in the US today - Corporations, the media, the universities, the NGOs. How many people in prominent (or even not prominent) positions in these instutions could get away with saying that whites are inherently smarter than blacks? I think there's very few institutions where, if it came to light that a person at one of these institutions said something to this effect, they would have any hope of keeping their job (or at the very least be disciplined and be made to attend ideological reconditioning classes). 

And virtually none of what Donald Trump said between 2015 - now remotely qualifies as this either - the most you can say is that what he says implies he doesn't like people who aren't white, or thinks they commit more crime etc. But anything remotely concerned with racial superiority is almost entirely just baseless allegations of particularly wild 'dog whistles' by his detractors. 

I don't know how to make sense of what you're saying other than to think you have a wildly incorrect understanding of the term 'Overton Window', and possibly that you believe anything short of radial 'anti-racist' ideology is tantamount to 'nazism'. 

It should also go without saying that thinking intelligence differences exist between populations is not remotely close to sufficient for someone to be a 'nazi'. One can hold such a view with almost any political ideology, and the average view of intelligence experts today is that the e.g. black/white IQ gap being to some extent heritable is the most likely reality. The obsession with 'good faith' and 'bad faith' is so weird in light of belief in potential scientific facts being casually referred to as 'nazisim'. 

What the nazis actually believed was that jews were no smarter than non-jews, but they were instead using their over-representation in positions of power in society to help jews as a group at the expense of everyone else, and that IQ tests were fake and used to justify jewish power. I'll leave you to work out the largest ideological group in America who believe something very analogous to this (hint: it's not people who voted for Trump). 

Most 'trans-women' I see online (in videos etc) who expliciltly identify themselves as such do not, to my eye, visually pass as women, even if I try and account for the fact that knowledge of their identity could skew my perception. It would be weird that every one of them I encounter IRL would fall into the minority of who clearly pass.

 Bezzi also said "meet", not just "see", which implies talking to the person, and I find that the numebr of 'trans-women' I see online who have voices that pass is even smaller than those who visually pass. It  therefore seems extremely unlikely that hundreds of the people I've met in my city who I thought were women were actually trans-women. 

Why do you insist on using on a loaded and truly meaningless word like "racism'? 

"American immigration policy is unwelcoming to immigrants."

Relative to the truly enormous number of people wishing to immigrate, perhaps. Pre-covid levels of over a million people a year are, however, truly enormous in an absolute sense, even if these people were randomly distributed across the entire country (they're not).