Extremism is born from the real sleeping danger of poor education and information standards which allow people to latch onto and be swayed by simplistic nonsense touted all too loudly on social media. When the rest of the world wore masks to protect the person next to them a loud section of the US population believed it was a plot to turn them Muslim. Similarly when the world understood the value of the developed vaccines a large part of the US thought it was a plot to implant tracking microchips - while carrying phones that were actually capable of tracking their activity. Every country has factions of this sort and the American population might have more reason than most to suspect government instructed mass vaccination programs but for a country with so much wealth the USA seems particularly prone to the sort of demagoguery that can take root in a poorly informed population. To put it more succinctly every day the film Idiocracy gets a little less funny.

The only bad extremism is right wing authoritarianism.

Left wing extremism = the civil rights movement