From what I've heard, the supreme court decision was mostly about the feds having access to the border, and the ability to cut down the razor wire, rather than any specific opposition to the razor wire existing in and of itself. I would wager this whole deal is mostly just a kind of political play, to try and egg biden into doing something stupid, while simultaneously keeping up the appearance that everyone at the head of these states is doing something dangerous, anti-institutional, and counter-cultural, even though they're all kind of inherently unable to do anything along those lines just as a matter of their positions.
Everybody's correct when they say that the political divides in this country are less clear-cut, but I also don't think that the radicalization that we've seen, as a matter of perspective from being in online space, necessarily reflects reality. I think if you look at most people, most people want social security of some kind, and want healthcare of some kind, and want drug legalization of some kind, and want us to stop fighting wars in some form. Those are all kind of generalities, because the specific mechanism by which people want those things achieved differs from person to person. It's very fractured as a matter of course, as a matter of how our political system and society is set up, and the ruling class has taken advantage of this to enact a divide and conquer strategy, where they can selectively promote whatever ideological positions benefit them the most, and cordon everyone off into a relatively small set of solutions over which they have a high amount of control. Rather than, you know, what a good democracy might do, which is come to a compromise solution, that everyone but the most extreme propagandized radicals might be kind of okay with. There is a reason why lots of conservatives like communism, as long as you use the right words. Both parties attempt to be mostly "populist" parties. This is all kind of obvious, right, but people understate the degree to which it's a deliberate thing, and the overstate the degree to which it's been successful, you know, which isn't surprising, because, again, serves the interests of the powerful. People aren't, broadly, morons, people have realized that this is all the case. That's mostly what the "radicalization" that you've seen online has been, people just realizing that they hate these shitass solutions that aren't really compromise solutions. See how everyone is cripplingly disappointed with the democratic party, and also how, likewise, conservatives are consistently disappointed with their own party, as well, and for many of the same reasons, barring the extreme radicals.
Most people are focused on how the internet divides people into radicalized swaths and conspiracy theorists, which is true, but even the mainstream monopolized internet is kind of a good tool for mass mobilization. See the occupy movement and the arab spring for older examples, for more recent examples, maybe the george floyd protests, or the french retirement protests. The only risk of these is kind of that they more easily get co-opted as a result of their visibility, i.e. "defund the police" gets turned into an argument for "fund the police". If you were an asshole, you could cite charlottesville, or jan 6th, for examples of internet mobilization, but those are relatively smaller scales of things, compared to the others, which were more popular, they just got disproportionate media attention relative to their size, and had disproportionate political effects.
I think if we're looking at the true, extreme political radicals, we're seeing them come about as a result of a kind of well-oiled engine. I'm not gonna say that this is an institutional kind of thing, and it's maybe more of a third level effect of active decisions, but it's still something that, nonetheless, has been deliberately constructed. 4chan is funded by a japanese toy company and a hands off japanese internet techbro, and is administrated by some former american military freak who's deliberately organized the site. The more radical offshoots, that use the same source code, tend to be funded by oil money, and political action committees, but through second-level effects, where they fund some small level conservative actor, and then they prop up the space. Which churns out some radical terrorists that are capable of your more fucked up bombings, and shootings, and controlled and coordinated protests. And then you kind of get military people at almost every level of this, in lower numbers, who act to control the space.
I dunno what I mean to extrapolate from all of this, but yeah. There's probably not going to be a civil war.