>>17793415 (OP)Brazilian historiography is awful, until a few years ago I'd say there were no serious studies about anything. Take a look at Portuguese Wikipedia entries about Brazilian history and you'll see that the French/English versions are way better because they know our own history better than us, due to them actually writing things down.
A huge sentiment among brazilians that try to study those things is the realization that they've been lied to, in schools we learn outdated and plainly wrong things about everything, not just history, but biology, geography, even math, I had a teacher that taught Malthusian thought as a fact, and couldn't understand that industrialization changed that. He still lived in the 1800s.
So when people learn about those things, that the monarchy wasn't the satan they make it be, and we see our political scandals on TV, it becomes only logical that people would go "hey maybe that monarchy thing is way better than this", it's not much about reality itself as it is about romanticism, I've been to a few congress of Liga Cristo Rei, and met the senior members of the Imperial Family back in Rio, they're well spoken intellectual men, and I'd be surprised if they'd be more of the same if they actually had any sort of influence in Brazilian affairs, but I don't think they actually want to go back to power, I think they're just keeping their family legacy alive, they're not doing anything wrong, and their views of a constitutional monarchy is completely opposed to what Brazil needs (I'm more of a Khmer Rouge enthusiast when it comes to dealing with our issues)
I don't know about those other causes, but I'd say it's a similar thing, the youth finding out they've been lied to, and going to the opposite extreme as a reaction to it.