To both of your points: the beer hall demagogue wouldn't have gotten to Chancellor if the German elites hadn't decided that he really couldn't do that much damage and we may as well let him be chancellor to quiet down his followers. Even after the putsch, he got a very light sentence because the judge was sympathetic with his right-wing cause. You're both right to some extent. A huge amount of damage was done by one man, but he got to where he did because the German elites thought that he might be useful to their cause.

Indeed, and that is perhaps the most important lesson of Hitlers rise - dangerous people will always exist, and so it is critical to have systems that are resilient to them, and not allow them to be hollowed out just because the current crop of leaders looks like they can be trusted with more power and less oversight, because who knows what kind of madman will get power next.

All events have multiple causes. But history turned on what he did, and would have been very different otherwise.

> what he did

Obviously, calling out for violence and building organizations that commit atrocious acts of violence is a bad thing.

However, it is really hard to do without the help of others.

If you start arguing that your country should invade your neighbors and mass murder various types of people, the people listening have a choice in how they react - do they politely remind you that we're generally happier and richer if we're nice to each other and "treat others like we'd like others to treat us", or shout "JAWOHL MEIN FURHER" and go invade neighbors and mass murdering undesirables?

The problem isn't always the guy shouting hate, it's the crowd listening and implementing hate.

The issue with beer hall demagogue is that their rise has been made only while the society at that time was so devastated in every sense (morally, economically, ...) that people saw them as the only hope against the status quo.

That's the moral of the story: if the present is so bad, and the elites refuse to change anything and just go push for their agendas against the will and the interest of common people, common people will support the devil himself if he is the only one promising he'll do something different.