Trump started as a meme on Reddit back in the day. r/thedonald was a joke/shitpost subreddit when he first announced he was running. And they would post comments like that to be funny because he was so obviously a joke candidate. Like, that was the guy from the apprentice and he was an idiot on the show . He bankrupted a casino!
Until it stopped being a joke. More and more posts popped up saying things like "I can't tell if we're still joking or if y'all are for real". And then they fully flipped into actually supporting him, and the right wing posting got both crazier and weirder. Now they're just full boot licking fascist psychos. Or bots. Probably both.