The best explanation I’ve come up with after discussing politics at length with them is that they are gaslit. Pure and simple. They just have enough gullibility to see one tiny thing that coincides with something they were taught or otherwise believe. It also explains why they are being scammed so easily on truthsocial.
Trump just has that dirty salesman skill of creating a story with just enough validity or truth and twisting everything to his favor.
There’s a lot more that we can add to that. Washington politics are so amazingly dirty, they have been for decades, everyone knows it, and Trump is different from other people. He’s actually even dirtier than most career politicians, but he feels different from them.
You also have the problem that some government institutions are corrupt and big business is very corrupt. It’s easier for people to imagine that conspiracy theories are true when they can openly see badness happening around them left unchecked. For example, if I watch on TV or YouTube and I see a court case where the prosecutor, lead detectives, and the judge are all incredibly biased and some of them are bad liars, then I know something is wrong with that courthouse. I might extrapolate and conclude that something is wrong with all courthouses. Which is to say, I’ve become more vulnerable to conspiracy theories because real bad behavior is left unchecked.
It’s also important not to forget the interpersonal aspect of how their lot get news. A lot of them believe their family and friends’ words more than a published news source. I see an echo to how urban myths got spread in pre-internet days: a neighbor’s cousin’s best friend’s coworker swears the story really happened to them! It must be true!
When a story is emotionally-engaging enough, it will get spread without ever being questioned. Trump’s path to power basically hijacked (and reinforced) that pre-existing tendency.
