> SF (and the US tech sphere at large) isn't an environment where people are taught to bridge the divide and understand others who think differently than they do.

You're painting a very diverse group with quite a broad brush. People in SF and the US tech sphere come from all over the place (even outside the US) and from many different backgrounds. People in US tech circles live and work side-by-side with people from all around the world, many of whom have been directly materially harmed by the right's politics. That's not an opinion or some kind of political position; it's a fact of life. From that, I can only assume that most Trump supporters either don't know people who come from different backgrounds, or simply don't care about or actively dislike such people. (And yes, of course there are exceptions to that! I know some of them.)

For my part, I try very hard to understand why people support Trump. The fact that a quarter of the country voted for him last November frankly scares me, and I want to understand why, and find ways to bridge the gap. I personally find support for him back in 2016 pretty understandable (if still a bit gross), but I'm scared for the future of the country that he still maintained so much support through 2020 despite his alarmingly high number of daily lies while he was in office, and his overwhelmingly racist, sexist, homophobic, transphobic, anti-science, anti-rational attitude. Over the past few years, I've talked to several people in person about their support of Trump (and right-leaning policies in general), but (with one single exception) they were all obstinate and unwilling to accept objective facts that conflicted with their ideology, to the point that they'd get defensive and angry and make further conversation pointless.

At this point the only reason I can see to support Trump is that you're so fed up with the establishment that you just want to watch the world burn, even if the guy doing the burning has based nearly all his policy positions on lies, and doesn't actually intend to help his supporters at all.

> But booting someone from YC for simply supporting a pretty mainstream viewpoint would be surprising, even in that environment.

As you noted, he wasn't booted for supporting a mainstream viewpoint; he was booted for harassing other YC founders with his political views, harassment that took a decidedly racist/xenophobic turn.

> But that doesn't mean all comments supporting a wall are necessarily racist. If you say "we need a border wall to stop cartels from profiting off of human trafficking, and should instead offer more visas for migrant workers from Central America," that's not a particularly racist view.

True, but unfortunately the overtly racist calls for a border wall tend to drown out the people who are attempting to be reasonable, so it's understandable for nearly anyone -- especially an immigrant -- to have a negative knee-jerk reaction to the topic.

Beyond that, where's the evidence that a border wall even helps with the things you're talking about? From what I understand, most human (and drug) trafficking takes place by plane or boat, or over land using legal ports of entry. And that's the thing that a lot of us find suspicious: the reasons stated for building a border wall might sound reasonable on the surface, but when you dig more, you find that a border wall doesn't actually make a meaningful dent in the problem being talked about. So then you can only draw one of two conclusions: either the person is woefully ignorant about the benefit of a border wall, or they know that a border wall isn't helpful and are just promoting it for xenophobic reasons. And when someone in the first camp still supports the wall after you give them evidence that it won't solve what they're talking about, they somehow still support it, so you naturally assume that they've actually been in the xenophobic camp the entire time.

Also, to zero in on one part of it:

> "... and should instead offer more visas for migrant workers from Central America"

Where are the border-wall-supporters who also support this? I haven't heard of any, but I do admit it's possible they're much quieter voices than the people who advocate for closing the border entirely, to the point of drowning them out.

But I've really veered too far off into politics-land, which tends not to contribute to productive discussion on HN, so I should probably stop...