Older American here, I remember the Before Times, so I can speak to how I've seen things change/crumble. Over the last twenty or so years everything has really accelerated. Social media is the biggest tool that outside and internal forces have used to destabilize democracy.
Democratic rule is terrible for business, people may make choices against your bottom line. On top of that, people like Iran, Russia, many others out there, want to crush America and never gave up their wars against us.
The KGB handbook details how to do what's been done to the US in great detail, how to amplify and boost the most confusing, chaotic rage-bait from both sides of every contentious issue until people basically tune out and just go along with whatever the government says. Makes people not get involved in electoral politics anymore. They did this in other countries that they've absorbed/annexed or have created sympathetic populations within.
If it was just Russia we probably could have countered it and defended better against it, but you combine that with the efforts of many other cells, different nations and contracted organizations doing the same thing, then add dopamine-addicting social-media algorithms and a deeply sabotaged education system, carefully tweaked interest rates and health-care obstacles, so that people are forced to work 6-days a week and are barely able to afford anything and can't spend any time learning or being curious, then a lot of very strategic messaging targeting specific portions of the population with racist, xenophobic ideas, and you have what we have now. A huge population held hostage by the smallest, dumbest, loudest segment.
And it's coming for you next.
(Also, this was all done before AI could specifically target every individual's most personal fears, desires and vulnerabilities, and could produce 100% convincing images and videos. We are all massively, thoroughly fucked.)