Now that I think about it more deeply, the biggest reason why this kind of constant, extreme, escalating, political violence is possible in the US, unlike in China for example, where the leading political party represents 100% of the people, is that in the US, their two parties represent only fractions of the population so they constantly need to brainwash people with fear and hatred against the other party to get votes or stay in power and win over the political opponent. The only way for them to increase their time in power is to slander and induce fear of the other party in people as much as possible. Then you have assassination attempts and people, from both political bases, hating each other (like that guy in the Twitter clip said he only hates Trump and Republicans and doesn't give a damn about anything else if he is the assassin). And then you have hundreds of years of such generational accumulation of indoctrination, and you get to today eventually. However, there are also other reasons, like general citizen satisfaction falling, over the recent decades. I think that this kind of system is bound to fail from the beginning eventually.