As others have pointed out, a lot of this is just mindless parroting for the sake of optics, but I can confirm from my personal life that a lot of otherwise rational people are actually denying reality. A difference from normal conspiracy theories I've noticed is that these aren't held deeply as deeply held as mainstream ones. The people I've talked to IRL about this haven't put up a lot of resistance to basic counterarguments like you'd expect from an actual Truther. Partially, I suspect this is because there isn't a wealth of detail that fuels continual scrutiny and most of the theories originate from arguing on Twitter over blurry cell phone footage.
My personal theory is that this whole phenomenon is the end result of severe cognitive dissonance on a mass scale. I'm not sure if there's any historical precedent for the kind of psychological reaction we're seeing. Liberals are simply unable to accept that this is what they've been reduced to: cheering for suicidal nutjobs to commit politicized gun violence. It goes against everything that has defined their political views for the last 30 years. A lot of this is because of their entrenched belief that we have managed to successfully to put ourselves on track for the Star Trek future exclusively via peaceful social change. Some influential examples of this line of thought include The End of History and the Last Man, and The Emerging Democratic Majority.
This is abundantly obvious to the posters in this thread, but the political reversals from the Obama-era have been mindbreaking for many normal people. The mental safety net your NPR-listening coworker had in place has been slowly becoming harder and harder to maintain faith in. The fact that nationalism and tradition have not been totally evaporated through the scientific rigor of globohomo ideology is source of existential dread for many normie liberals. Why? Because it implies that progressive social democracy is an imperfect system that has no inherent value to it. Many liberals hold the subconscious belief that all third-world hell holes are only the way they are because they haven't democracy'd away their dystopias yet. To make realistic arguments about the external effects that geography, demographics, and culture is a source of distress because that implies that their political system (which essentially doubles as a religion) is not the panacea that they have been brought up to believe.
How this relates to the current predicament of political violence in the US is twofold: they are unable to accept that pacifism has failed to deliver utopian results and they lack the ideological depth needed to understand the role of violence in political history. The very democratic system we use to (ideally) avoid the use of violence, was itself developed through multiple deadly conflicts. It's simply a reality that every successful social change, positive or negative, either overtly or implicitly uses violence to achieve its goals. The difference depends on understanding the appropriate use of force rather than avoiding it on a matter of principle. This is why the shift to hawkishness from liberals regarding the Ukrainian War came off as so jarring for me. The same people who want to disarm the populace, pursue restorative justice policies, and abolish national borders were cheering on a violent enthonationalist conflict where you can watch memes of soldiers getting blown to pieces or summarily executed.
The point I'm trying here to make is that this bizarre NPC-like shift in thinking is the result of having a massive blind spot in their worldview regarding violence mixed with the continued discouragement of independent thought. They simply don't have the vocabulary to explain why force is necessary to defend "their democracy" nor what parameters its use should follow. The somewhat more aware ones will attempt to soothe their psyche by playing the same word-games they did with Charlie Kirk ("I don't support what happened but they had it coming"), but many have been opting to straight up deny this is the world they're living in ("LOOK HE'S WEARING A MCDONALDS SHIRT, THE HAMBURGLER SET THIS UP").
In both cases, but mostly the latter, this stems from a desire to avoid having to confront some very ugly truths about the world. Casting everything as a psyop or inside job assigns a level of control for the external world. It's somewhat counterintuitive, but these kinds of conspiracy theories are more often used as source of comfort for the people who engage with them. Because in this view, even though the state of the world might be undesirable, at least someone's controlling it. Otherwise, you might have to consider the possibility that nobody's controlling it and we exist in perpetual state of genuine uncertainty. This can be a very, very challenging idea to deal with, especially when you've been discouraged from doing so for multiple generations.
