Has anyone done any work on why people became communists, nazis or fascists?

Anyone inquired as to why some Native Americans got "radicalised" and rejected the authority imposed upon them?

My point is, if what is radicalising them is "the political reality" then the only real issue is do they express their politics using violence. - if they do that, then kill or incarcerate them, in line with what the law allows.
Nothing you can or or say, will stop some kid becoming a suicide bomber - and if you can, then he's not one of the ones to worry about.