A lot of you cats are missing the point.
OP is not asking why Hitler become powerful. He's asking how. Saying he hated Jews, which is true, is not the answer. That's one of the reasons he wanted power. Not reason he took power. A lot of people hated Jews but they did not become powerful. Saying Germany was in bad shape is not an answer neither. The economic depression in Germany created the conditions for someone like Hitler to take power but it doesn't explain why Hitler took that spot.
There was an individual and political process that took him from being a mere caporal to the more powerful man in Germany.
The first step is to know what other players were involved in the game in that period.
It's dangerous because another Hitler could rise tomorrow and people won't see him. You need to understand the process to stop it.
Agreed.
Hitler and the Nazis were neither the first right-wing, anti-Semitic political party in Germany, nor were they responsible for the rise of that anti-Semitism in the first place. The German Army was, because they started the “stab-in-the-back” myth after losing in WWI. And even though Hitler and the Nazis did become popular in the 1920s, that only explains the
why of how they came into power (they offered a popular support base), not the
how, because 1930s Germany wasn't a democracy. Hitler wasn’t elected to his position by the German people.
The reason Hitler got powerful was because Hindenburg and the German Right, thinking that Hitler would be an easily-manipulated idiot to be used for their purposes, appointed him to his position. As it turned out, they were wrong, because Hitler ended up either killing most of them or throwing them in jail, and he took power for himself. But that could only happen once he was Chancellor. If that never happened, the Nazis would likely have faded into obscurity and no one today would know who Hitler even was.